diff --git a/.phpstan.dist.baselines/_loader.php b/.phpstan.dist.baselines/_loader.php
index 3d14cefd84a..b59aec7395a 100644
--- a/.phpstan.dist.baselines/_loader.php
+++ b/.phpstan.dist.baselines/_loader.php
@@ -58,7 +58,6 @@
     __DIR__ . '/if.alwaysTrue.php',
     __DIR__ . '/if.condNotBoolean.php',
     __DIR__ . '/instanceof.alwaysTrue.php',
-    __DIR__ . '/isset.variable.php',
     __DIR__ . '/method.childParameterType.php',
     __DIR__ . '/method.childReturnType.php',
     __DIR__ . '/method.deprecated.php',
diff --git a/.phpstan.dist.baselines/argument.type.php b/.phpstan.dist.baselines/argument.type.php
index bc930b84ca9..6ad9cc0aa55 100644
--- a/.phpstan.dist.baselines/argument.type.php
+++ b/.phpstan.dist.baselines/argument.type.php
@@ -951,16 +951,6 @@
     'count' => 2,
     'path' => __DIR__ . '/../app/code/core/Mage/Api/Model/Wsdl/Config/Element.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Parameter #1 $array of function uasort expects array, array|string given.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Api2/Helper/Data.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'Parameter #2 $string of function explode expects string, string|true given.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Api2/Helper/Data.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Parameter #1 $roleId of method Mage_Api2_Model_Acl::addRole() expects int, int|string|null given.',
     'count' => 1,
@@ -4891,16 +4881,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Payment/Exception.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Parameter #2 $haystack of function in_array expects array, array<string, class-string>|false given.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Helper/Data.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'Parameter #1 $array of function uasort expects array, array|string given.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Model/Config.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Parameter #2 $array of function array_key_exists expects array, array|int given.',
     'count' => 1,
diff --git a/.phpstan.dist.baselines/assign.propertyType.php b/.phpstan.dist.baselines/assign.propertyType.php
index 5e140fa8a59..2d9bcd53ee1 100644
--- a/.phpstan.dist.baselines/assign.propertyType.php
+++ b/.phpstan.dist.baselines/assign.propertyType.php
@@ -431,11 +431,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Index/Model/Resource/Lock/Resource.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Property Varien_Data_Collection_Db<Mage_Core_Model_Abstract>::$_map (array{fields: array<string, string>}|null) does not accept array{fields: non-empty-array<string, string|Zend_Db_Expr>}.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Newsletter/Model/Resource/Subscriber/Collection.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Property Mage_Page_Block_Html_Pager::$_frameEnd (int) does not accept float|int.',
     'count' => 1,
@@ -581,16 +576,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../lib/Mage/HTTP/Client/Socket.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Property Varien_Data_Collection_Db<T of Varien_Object>::$_map (array{fields: array<string, string>}|null) does not accept non-empty-array<string, array<string, string>>.',
-    'count' => 2,
-    'path' => __DIR__ . '/../lib/Varien/Data/Collection/Db.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'Property Varien_Data_Collection_Db<T of Varien_Object>::$_map (array{fields: array<string, string>}|null) does not accept non-empty-array<string, array{}>.',
-    'count' => 1,
-    'path' => __DIR__ . '/../lib/Varien/Data/Collection/Db.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Property Varien_Data_Form_Filter_Date::$_locale (string|Zend_Locale) does not accept string|Zend_Locale|null.',
     'count' => 1,
diff --git a/.phpstan.dist.baselines/booleanAnd.leftNotBoolean.php b/.phpstan.dist.baselines/booleanAnd.leftNotBoolean.php
index 501368db3a1..487b2d6a25d 100644
--- a/.phpstan.dist.baselines/booleanAnd.leftNotBoolean.php
+++ b/.phpstan.dist.baselines/booleanAnd.leftNotBoolean.php
@@ -1591,16 +1591,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Payment/Block/Info/Container.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Only booleans are allowed in &&, Mage_Payment_Model_Method_Abstract given on the left side.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Helper/Data.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'Only booleans are allowed in &&, object|false given on the left side.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Model/Config.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Only booleans are allowed in &&, string|null given on the left side.',
     'count' => 1,
diff --git a/.phpstan.dist.baselines/booleanNot.exprNotBoolean.php b/.phpstan.dist.baselines/booleanNot.exprNotBoolean.php
index 3f04f86addb..6e742b142aa 100644
--- a/.phpstan.dist.baselines/booleanNot.exprNotBoolean.php
+++ b/.phpstan.dist.baselines/booleanNot.exprNotBoolean.php
@@ -1111,11 +1111,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Api/Model/Wsdl/Config/Element.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Only booleans are allowed in a negated boolean, Mage_Core_Model_Config_Element|false given.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Api2/Helper/Data.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Only booleans are allowed in a negated boolean, array given.',
     'count' => 1,
@@ -5046,21 +5041,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Payment/Block/Info.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Only booleans are allowed in a negated boolean, Mage_Payment_Model_Method_Abstract|false given.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Helper/Data.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'Only booleans are allowed in a negated boolean, mixed given.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Helper/Data.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'Only booleans are allowed in a negated boolean, string|null given.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Helper/Data.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Only booleans are allowed in a negated boolean, string given.',
     'count' => 1,
diff --git a/.phpstan.dist.baselines/equal.notAllowed.php b/.phpstan.dist.baselines/equal.notAllowed.php
index dabfcf1dfaf..651a03adf20 100644
--- a/.phpstan.dist.baselines/equal.notAllowed.php
+++ b/.phpstan.dist.baselines/equal.notAllowed.php
@@ -4361,11 +4361,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Payment/Block/Info/Container.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Loose comparison via "==" between mixed and mixed is not allowed.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Model/Config.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Loose comparison via "==" between mixed and int is not allowed.',
     'count' => 1,
diff --git a/.phpstan.dist.baselines/foreach.nonIterable.php b/.phpstan.dist.baselines/foreach.nonIterable.php
index 4e240a0e480..1fffab91ce2 100644
--- a/.phpstan.dist.baselines/foreach.nonIterable.php
+++ b/.phpstan.dist.baselines/foreach.nonIterable.php
@@ -96,11 +96,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Api/Model/Resource/User.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Argument of an invalid type array|string supplied for foreach, only iterables are supported.',
-    'count' => 2,
-    'path' => __DIR__ . '/../app/code/core/Mage/Api2/Helper/Data.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Argument of an invalid type list<string>|false supplied for foreach, only iterables are supported.',
     'count' => 1,
@@ -471,16 +466,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Payment/Block/Info.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Argument of an invalid type array|string supplied for foreach, only iterables are supported.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Helper/Data.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'Argument of an invalid type array|string supplied for foreach, only iterables are supported.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Model/Config.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Argument of an invalid type array<Varien_Simplexml_Element>|false|null supplied for foreach, only iterables are supported.',
     'count' => 1,
diff --git a/.phpstan.dist.baselines/function.strict.php b/.phpstan.dist.baselines/function.strict.php
index ee1b3c51959..b92ffdaadd3 100644
--- a/.phpstan.dist.baselines/function.strict.php
+++ b/.phpstan.dist.baselines/function.strict.php
@@ -311,11 +311,6 @@
     'count' => 2,
     'path' => __DIR__ . '/../app/code/core/Mage/Api/Model/Wsdl/Config/Base.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Call to function in_array() requires parameter #3 to be set.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Api2/Helper/Data.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Call to function in_array() requires parameter #3 to be set.',
     'count' => 1,
@@ -1216,11 +1211,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Paygate/Model/Authorizenet.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Call to function in_array() requires parameter #3 to be set.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Helper/Data.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Call to function in_array() requires parameter #3 to be set.',
     'count' => 1,
diff --git a/.phpstan.dist.baselines/if.condNotBoolean.php b/.phpstan.dist.baselines/if.condNotBoolean.php
index d0010742a10..44af555c33c 100644
--- a/.phpstan.dist.baselines/if.condNotBoolean.php
+++ b/.phpstan.dist.baselines/if.condNotBoolean.php
@@ -2121,11 +2121,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Api2/Block/Adminhtml/Permissions/User/Edit/Tab/Roles.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Only booleans are allowed in an if condition, Mage_Core_Model_Config_Element|false given.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Api2/Helper/Data.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Only booleans are allowed in an if condition, array given.',
     'count' => 1,
@@ -6461,16 +6456,6 @@
     'count' => 2,
     'path' => __DIR__ . '/../app/code/core/Mage/Payment/Block/Info/Container.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Only booleans are allowed in an if condition, Mage_Core_Model_Layout given.',
-    'count' => 2,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Helper/Data.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'Only booleans are allowed in an if condition, string|null given.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Helper/Data.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Only booleans are allowed in an if condition, Mage_Payment_Model_Method_Abstract|false given.',
     'count' => 1,
diff --git a/.phpstan.dist.baselines/isset.variable.php b/.phpstan.dist.baselines/isset.variable.php
deleted file mode 100644
index 5d6dbb5f2f1..00000000000
--- a/.phpstan.dist.baselines/isset.variable.php
+++ /dev/null
@@ -1,10 +0,0 @@
-<?php declare(strict_types = 1);
-
-$ignoreErrors = [];
-$ignoreErrors[] = [
-    'rawMessage' => 'Variable $destination in isset() always exists and is always null.',
-    'count' => 1,
-    'path' => __DIR__ . '/../lib/Varien/Image/Adapter/Gd2.php',
-];
-
-return ['parameters' => ['ignoreErrors' => $ignoreErrors]];
diff --git a/.phpstan.dist.baselines/method.nonObject.php b/.phpstan.dist.baselines/method.nonObject.php
index 04ed310b7ff..7be2cb4a844 100644
--- a/.phpstan.dist.baselines/method.nonObject.php
+++ b/.phpstan.dist.baselines/method.nonObject.php
@@ -2001,11 +2001,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Api2/Block/Adminhtml/Roles/Tab/Users.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Cannot call method getNode() on Mage_Core_Model_Config|null.',
-    'count' => 2,
-    'path' => __DIR__ . '/../app/code/core/Mage/Api2/Helper/Data.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Cannot call method children() on array|Varien_Simplexml_Element.',
     'count' => 1,
@@ -4896,36 +4891,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Payment/Block/Info/Container.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Cannot call method asCanonicalArray() on Mage_Core_Model_Config_Element|false.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Helper/Data.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'Cannot call method getBlockClassName() on Mage_Core_Model_Config|null.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Helper/Data.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'Cannot call method getConfigData() on object|false.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Helper/Data.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'Cannot call method setMethod() on Mage_Core_Block_Abstract|false.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Helper/Data.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'Cannot call method asArray() on Mage_Core_Model_Config_Element|false.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Model/Config.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'Cannot call method getNode() on Mage_Core_Model_Config|null.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Model/Config.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Cannot call method getCountryId() on Mage_Sales_Model_Order_Address|false.',
     'count' => 1,
diff --git a/.phpstan.dist.baselines/method.notFound.php b/.phpstan.dist.baselines/method.notFound.php
index b7df587f3e1..94897b5a5cb 100644
--- a/.phpstan.dist.baselines/method.notFound.php
+++ b/.phpstan.dist.baselines/method.notFound.php
@@ -1351,11 +1351,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Paygate/controllers/Authorizenet/PaymentController.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Call to an undefined method object::getConfigData().',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Model/Config.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Call to an undefined method object::setTemplate().',
     'count' => 1,
diff --git a/.phpstan.dist.baselines/missingType.iterableValue.php b/.phpstan.dist.baselines/missingType.iterableValue.php
index 87825bec716..4e549204a60 100644
--- a/.phpstan.dist.baselines/missingType.iterableValue.php
+++ b/.phpstan.dist.baselines/missingType.iterableValue.php
@@ -19191,11 +19191,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Payment/Block/Info/Ccsave.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Method Mage_Payment_Helper_Data::getAllBillingAgreementMethods() return type has no value type specified in iterable type array.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Helper/Data.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Method Mage_Payment_Helper_Data::getPaymentMethodList() return type has no value type specified in iterable type array.',
     'count' => 1,
@@ -19226,26 +19221,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Payment/Model/Config.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Method Mage_Payment_Model_Config::getActiveMethods() return type has no value type specified in iterable type array.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Model/Config.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'Method Mage_Payment_Model_Config::getAllMethods() return type has no value type specified in iterable type array.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Model/Config.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'Method Mage_Payment_Model_Config::getMonths() return type has no value type specified in iterable type array.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Model/Config.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'Method Mage_Payment_Model_Config::getYears() return type has no value type specified in iterable type array.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Model/Config.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Method Mage_Payment_Model_Info::setAdditionalInformation() has parameter $key with no value type specified in iterable type array.',
     'count' => 1,
diff --git a/.phpstan.dist.baselines/missingType.parameter.php b/.phpstan.dist.baselines/missingType.parameter.php
index 05f3a1e9c3e..1225dc83797 100644
--- a/.phpstan.dist.baselines/missingType.parameter.php
+++ b/.phpstan.dist.baselines/missingType.parameter.php
@@ -1196,11 +1196,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Paygate/Model/Authorizenet/Cards.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Method Mage_Payment_Helper_Data::getMethodModelClassName() has parameter $code with no type specified.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Helper/Data.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Method Mage_Paypal_Block_Adminhtml_System_Config_Fieldset_Global::getElementOriginalData() has parameter $key with no type specified.',
     'count' => 1,
diff --git a/.phpstan.dist.baselines/missingType.property.php b/.phpstan.dist.baselines/missingType.property.php
index 2cd67b2f902..20431ec7357 100644
--- a/.phpstan.dist.baselines/missingType.property.php
+++ b/.phpstan.dist.baselines/missingType.property.php
@@ -2536,11 +2536,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Payment/Exception.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Property Mage_Payment_Model_Config::$_methods has no type specified.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Model/Config.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Property Mage_Payment_Model_Method_Abstract::$_canAuthorize has no type specified.',
     'count' => 1,
diff --git a/.phpstan.dist.baselines/property.notFound.php b/.phpstan.dist.baselines/property.notFound.php
index 483f4c1c942..d94a36b198b 100644
--- a/.phpstan.dist.baselines/property.notFound.php
+++ b/.phpstan.dist.baselines/property.notFound.php
@@ -31,11 +31,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Customer/Model/Customer.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Access to an undefined property object::$sort_order.',
-    'count' => 2,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Helper/Data.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Access to an undefined property object::$Code.',
     'count' => 3,
diff --git a/.phpstan.dist.baselines/return.type.php b/.phpstan.dist.baselines/return.type.php
index f68913cdf90..15ba04b727b 100644
--- a/.phpstan.dist.baselines/return.type.php
+++ b/.phpstan.dist.baselines/return.type.php
@@ -431,11 +431,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Api/Model/User.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Method Mage_Api2_Helper_Data::getAuthAdapters() should return array but returns array|string.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Api2/Helper/Data.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Method Mage_Api2_Model_Config::getResourceAttributes() should return array but returns array|string.',
     'count' => 1,
@@ -2361,16 +2356,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Payment/Block/Form.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Method Mage_Payment_Helper_Data::getMethodFormBlock() should return Mage_Core_Block_Abstract but returns Mage_Core_Block_Abstract|false.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Helper/Data.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'Method Mage_Payment_Helper_Data::getMethodInstance() should return Mage_Payment_Model_Method_Abstract|false but returns object|false.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Payment/Helper/Data.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Method Mage_Payment_Model_Billing_AgreementAbstract::getPaymentMethodInstance() should return Mage_Payment_Model_Method_Abstract|null but returns Mage_Payment_Model_Method_Abstract|false.',
     'count' => 1,
diff --git a/.phpstan.dist.baselines/variable.undefined.php b/.phpstan.dist.baselines/variable.undefined.php
index 71a65a78611..0b5545ed0f5 100644
--- a/.phpstan.dist.baselines/variable.undefined.php
+++ b/.phpstan.dist.baselines/variable.undefined.php
@@ -6,11 +6,6 @@
     'count' => 2,
     'path' => __DIR__ . '/../app/code/core/Mage/Adminhtml/Model/Sales/Order/Create.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Variable $adapters might not be defined.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Api2/Helper/Data.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Variable $operationName might not be defined.',
     'count' => 2,
diff --git a/app/code/core/Mage/Api2/Helper/Data.php b/app/code/core/Mage/Api2/Helper/Data.php
index b0404ed7d46..ccc8822a766 100644
--- a/app/code/core/Mage/Api2/Helper/Data.php
+++ b/app/code/core/Mage/Api2/Helper/Data.php
@@ -53,25 +53,23 @@ protected static function _compareOrder($a, $b)
      */
     public function getAuthAdapters($enabledOnly = false)
     {
-        $adapters = Mage::getConfig()->getNode(self::XML_PATH_AUTH_ADAPTERS);
+        $adapters = Mage::getConfig()?->getNode(self::XML_PATH_AUTH_ADAPTERS);
 
-        if (!$adapters) {
+        if (!$adapters instanceof Varien_Simplexml_Element) {
             return [];
         }
 
         $adapters = $adapters->asArray();
 
-        if ($enabledOnly) {
-            foreach ($adapters as $adapter) {
-                if (empty($adapter['enabled'])) {
-                    unset($adapters);
-                }
-            }
+        if (!is_array($adapters)) {
+            return [];
+        }
 
-            $adapters = (array) $adapters;
+        if ($enabledOnly) {
+            $adapters = array_filter($adapters, fn($adapter) => !empty($adapter['enabled']));
         }
 
-        uasort($adapters, ['Mage_Api2_Helper_Data', '_compareOrder']);
+        uasort($adapters, self::_compareOrder(...));
 
         return $adapters;
     }
@@ -83,14 +81,22 @@ public function getAuthAdapters($enabledOnly = false)
      */
     public function getUserTypes()
     {
-        $userModels = [];
-        $types = Mage::getConfig()->getNode(self::XML_PATH_USER_TYPES);
+        $types = Mage::getConfig()?->getNode(self::XML_PATH_USER_TYPES);
+
+        if (!$types instanceof Varien_Simplexml_Element) {
+            return [];
+        }
 
-        if ($types) {
-            foreach ($types->asArray() as $type => $params) {
-                if (!empty($params['allowed'])) {
-                    $userModels[$type] = $params['model'];
-                }
+        $types = $types->asArray();
+
+        if (!is_array($types)) {
+            return [];
+        }
+
+        $userModels = [];
+        foreach ($types as $type => $params) {
+            if (!empty($params['allowed'])) {
+                $userModels[$type] = $params['model'];
             }
         }
 
@@ -125,7 +131,7 @@ public function getResponseRenderAdapters()
      */
     public function isApiTypeSupported($type)
     {
-        return in_array($type, Mage_Api2_Model_Server::getApiTypes());
+        return in_array($type, Mage_Api2_Model_Server::getApiTypes(), true);
     }
 
     /**
diff --git a/app/code/core/Mage/Api2/Model/Resource/Acl/Filter/Attribute.php b/app/code/core/Mage/Api2/Model/Resource/Acl/Filter/Attribute.php
index b0b3de73f5f..514c32d7dab 100644
--- a/app/code/core/Mage/Api2/Model/Resource/Acl/Filter/Attribute.php
+++ b/app/code/core/Mage/Api2/Model/Resource/Acl/Filter/Attribute.php
@@ -31,7 +31,7 @@ protected function _construct()
      * @param  string                                          $userType
      * @param  string                                          $resourceId
      * @param  Mage_Api2_Model_Resource::OPERATION_ATTRIBUTE_* $operation
-     * @return null|bool|string
+     * @return null|false|string
      */
     public function getAllowedAttributes($userType, $resourceId, $operation)
     {
diff --git a/app/code/core/Mage/Payment/Block/Form.php b/app/code/core/Mage/Payment/Block/Form.php
index 6597ebed517..763faaf8a5e 100644
--- a/app/code/core/Mage/Payment/Block/Form.php
+++ b/app/code/core/Mage/Payment/Block/Form.php
@@ -11,6 +11,8 @@
  * Payment method form base block
  *
  * @package    Mage_Payment
+ *
+ * @method $this setMethod(Mage_Payment_Model_Method_Abstract $method)
  */
 class Mage_Payment_Block_Form extends Mage_Core_Block_Template
 {
diff --git a/app/code/core/Mage/Payment/Block/Info.php b/app/code/core/Mage/Payment/Block/Info.php
index 29c181a34bf..33293eac04b 100644
--- a/app/code/core/Mage/Payment/Block/Info.php
+++ b/app/code/core/Mage/Payment/Block/Info.php
@@ -12,7 +12,8 @@
  *
  * @package    Mage_Payment
  *
- * @method bool hasIsSecureMode()
+ * @method bool  hasIsSecureMode()
+ * @method $this setInfo(Mage_Payment_Model_Info $info)
  */
 class Mage_Payment_Block_Info extends Mage_Core_Block_Template
 {
diff --git a/app/code/core/Mage/Payment/Helper/Data.php b/app/code/core/Mage/Payment/Helper/Data.php
index 3db90cf190b..7d15d37bf47 100644
--- a/app/code/core/Mage/Payment/Helper/Data.php
+++ b/app/code/core/Mage/Payment/Helper/Data.php
@@ -25,13 +25,14 @@ class Mage_Payment_Helper_Data extends Mage_Core_Helper_Abstract
     /**
      * Retrieve the class name of the payment method's model
      *
-     * @param              $code
+     * @param  string        $code
+     * @param  ConfigStoreId $store
      * @return null|string
      */
-    public function getMethodModelClassName($code)
+    public function getMethodModelClassName($code, $store = null)
     {
         $key = self::XML_PATH_PAYMENT_METHODS . '/' . $code . '/model';
-        return Mage::getStoreConfig($key);
+        return Mage::getStoreConfig($key, $store);
     }
 
     /**
@@ -48,7 +49,11 @@ public function getMethodInstance($code)
             return false;
         }
 
-        return Mage::getModel($class);
+        /**
+         * @var false|Mage_Payment_Model_Method_Abstract $model
+         */
+        $model = Mage::getModel($class);
+        return $model;
     }
 
     /**
@@ -65,14 +70,14 @@ public function getStoreMethods($store = null, $quote = null)
     {
         $res = [];
         foreach (array_keys($this->getPaymentMethods($store)) as $code) {
-            $prefix = self::XML_PATH_PAYMENT_METHODS . '/' . $code . '/';
-            if (!$model = Mage::getStoreConfig($prefix . 'model', $store)) {
+            $model = $this->getMethodModelClassName($code, $store);
+            if (!is_string($model)) {
                 continue;
             }
 
             /** @var false|Mage_Payment_Model_Method_Abstract $methodInstance */
             $methodInstance = Mage::getModel($model);
-            if (!$methodInstance) {
+            if (!$methodInstance instanceof Mage_Payment_Model_Method_Abstract) {
                 continue;
             }
 
@@ -82,8 +87,6 @@ public function getStoreMethods($store = null, $quote = null)
                 continue;
             }
 
-            $sortOrder = (int) $methodInstance->getConfigData('sort_order', $store);
-            $methodInstance->setSortOrder($sortOrder);
             $res[] = $methodInstance;
         }
 
@@ -92,14 +95,14 @@ public function getStoreMethods($store = null, $quote = null)
     }
 
     /**
-     * @param  object $a
-     * @param  object $b
+     * @param  Mage_Payment_Model_Method_Abstract $a
+     * @param  Mage_Payment_Model_Method_Abstract $b
      * @return int
      */
     protected function _sortMethods($a, $b)
     {
         if (is_object($a)) {
-            return (int) $a->sort_order <=> (int) $b->sort_order;
+            return $a->getSortOrder() <=> $b->getSortOrder();
         }
 
         return 0;
@@ -108,37 +111,39 @@ protected function _sortMethods($a, $b)
     /**
      * Retrieve payment method form html
      *
-     * @return Mage_Core_Block_Abstract|Mage_Payment_Block_Form
+     * @return Mage_Payment_Block_Form
      */
     public function getMethodFormBlock(Mage_Payment_Model_Method_Abstract $method)
     {
-        $block = false;
         $blockType = $method->getFormBlockType();
-        if ($this->getLayout()) {
+        if ($this->getLayout() !== null) {
             $block = $this->getLayout()->createBlock($blockType);
-            $block->setMethod($method);
+        } else {
+            $className = Mage::app()->getConfig()->getBlockClassName($blockType);
+            $block = new $className();
         }
-
+        /** @var Mage_Payment_Block_Form $block */
+        $block->setMethod($method);
         return $block;
     }
 
     /**
      * Retrieve payment information block
      *
-     * @return Mage_Core_Block_Abstract
+     * @return Mage_Payment_Block_Info
      * @throws Mage_Core_Exception
      */
     public function getInfoBlock(Mage_Payment_Model_Info $info)
     {
         $blockType = $info->getMethodInstance()->getInfoBlockType();
-        if ($this->getLayout()) {
+        if ($this->getLayout() !== null) {
             $block = $this->getLayout()->createBlock($blockType);
         } else {
-            $className = Mage::getConfig()->getBlockClassName($blockType);
+            $className = Mage::app()->getConfig()->getBlockClassName($blockType);
             $block = new $className();
         }
 
-        /** @var Mage_Core_Block_Abstract $block */
+        /** @var Mage_Payment_Block_Info $block */
         $block->setInfo($info);
         return $block;
     }
@@ -172,14 +177,14 @@ public function getRecurringProfileMethods($store = null)
     {
         $result = [];
         foreach (array_keys($this->getPaymentMethods($store)) as $code) {
-            $paymentMethodModelClassName = $this->getMethodModelClassName($code);
-            if (!$paymentMethodModelClassName) {
+            $paymentMethodModelClassName = $this->getMethodModelClassName($code, $store);
+            if (!is_string($paymentMethodModelClassName)) {
                 continue;
             }
 
             /** @var Mage_Payment_Model_Method_Abstract $method */
             $method = Mage::getModel($paymentMethodModelClassName);
-            if ($method && $method->canManageRecurringProfiles()) {
+            if ($method instanceof Mage_Payment_Model_Method_Abstract && $method->canManageRecurringProfiles()) {
                 $result[] = $method;
             }
         }
@@ -231,8 +236,11 @@ public function getPaymentMethodList($sorted = true, $asLabelValue = false, $wit
                 $methods[$code] = $data['title'];
             } else {
                 $paymentMethodModelClassName = $this->getMethodModelClassName($code);
-                if ($paymentMethodModelClassName) {
-                    $methods[$code] = Mage::getModel($paymentMethodModelClassName)->getConfigData('title', $store);
+                if (is_string($paymentMethodModelClassName)) {
+                    $methodModel = Mage::getModel($paymentMethodModelClassName);
+                    if ($methodModel instanceof Mage_Payment_Model_Method_Abstract) {
+                        $methods[$code] = $methodModel->getConfigData('title', $store);
+                    }
                 }
             }
 
@@ -242,7 +250,18 @@ public function getPaymentMethodList($sorted = true, $asLabelValue = false, $wit
         }
 
         if ($asLabelValue && $withGroups) {
-            $groups = Mage::app()->getConfig()->getNode(self::XML_PATH_PAYMENT_GROUPS)->asCanonicalArray();
+            $groups = Mage::app()->getConfig()->getNode(self::XML_PATH_PAYMENT_GROUPS);
+
+            if ($groups instanceof Varien_Simplexml_Element) {
+                $groups = $groups->asCanonicalArray();
+
+                if (!is_array($groups)) {
+                    $groups = [];
+                }
+            } else {
+                $groups = [];
+            }
+
             foreach ($groups as $code => $title) {
                 $methods[$code] = $title; // for sorting, see below
             }
@@ -278,19 +297,18 @@ public function getPaymentMethodList($sorted = true, $asLabelValue = false, $wit
     /**
      * Retrieve all billing agreement methods (code and label)
      *
-     * @return array
+     * @return array<string, string>
      */
     public function getAllBillingAgreementMethods()
     {
         $result = [];
-        $interface = 'Mage_Payment_Model_Billing_Agreement_MethodInterface';
         foreach ($this->getPaymentMethods() as $code => $data) {
             if (!isset($data['model'])) {
                 continue;
             }
 
             $method = Mage::app()->getConfig()->getModelClassName($data['model']);
-            if (in_array($interface, class_implements($method))) {
+            if (is_a($method, Mage_Payment_Model_Billing_Agreement_MethodInterface::class, true)) {
                 $result[$code] = $data['title'];
             }
         }
diff --git a/app/code/core/Mage/Payment/Model/Config.php b/app/code/core/Mage/Payment/Model/Config.php
index b98e29fe623..5081d32c6a6 100644
--- a/app/code/core/Mage/Payment/Model/Config.php
+++ b/app/code/core/Mage/Payment/Model/Config.php
@@ -18,13 +18,16 @@
  */
 class Mage_Payment_Model_Config
 {
+    /**
+     * @var array<string, Mage_Payment_Model_Method_Abstract>
+     */
     protected static $_methods;
 
     /**
      * Retrieve active system payments
      *
-     * @param  ConfigStoreId $store
-     * @return array
+     * @param  ConfigStoreId                                     $store
+     * @return array<string, Mage_Payment_Model_Method_Abstract>
      */
     public function getActiveMethods($store = null)
     {
@@ -32,9 +35,9 @@ public function getActiveMethods($store = null)
         $config = Mage::getStoreConfig('payment', $store);
         foreach ($config as $code => $methodConfig) {
             if (Mage::getStoreConfigFlag('payment/' . $code . '/active', $store) && array_key_exists('model', $methodConfig)) {
-                $methodModel = Mage::getModel($methodConfig['model']);
-                if ($methodModel && $methodModel->getConfigData('active', $store)) {
-                    $methods[$code] = $this->_getMethod($code, $methodConfig);
+                $methodModel = $this->_getMethod($code, $methodConfig, $store);
+                if ($methodModel !== false && (bool) (int) $methodModel->getConfigData('active', $store)) {
+                    $methods[$code] = $methodModel;
                 }
             }
         }
@@ -45,15 +48,15 @@ public function getActiveMethods($store = null)
     /**
      * Retrieve all system payments
      *
-     * @param  ConfigStoreId $store
-     * @return array
+     * @param  ConfigStoreId                                     $store
+     * @return array<string, Mage_Payment_Model_Method_Abstract>
      */
     public function getAllMethods($store = null)
     {
         $methods = [];
         $config = Mage::getStoreConfig('payment', $store);
         foreach ($config as $code => $methodConfig) {
-            $data = $this->_getMethod($code, $methodConfig);
+            $data = $this->_getMethod($code, $methodConfig, $store);
             if ($data !== false) {
                 $methods[$code] = $data;
             }
@@ -63,14 +66,15 @@ public function getAllMethods($store = null)
     }
 
     /**
-     * @param  string                                     $code
-     * @param  array                                      $config
-     * @param  null|bool|int|Mage_Core_Model_Store|string $store  $store
+     * @param  string                                   $code
+     * @param  array                                    $config
+     * @param  ConfigStoreId                            $store
      * @return false|Mage_Payment_Model_Method_Abstract
      */
     protected function _getMethod($code, $config, $store = null)
     {
         if (isset(self::$_methods[$code])) {
+            self::$_methods[$code]->setStore($store);
             return self::$_methods[$code];
         }
 
@@ -98,9 +102,19 @@ protected function _getMethod($code, $config, $store = null)
      */
     public function getCcTypes()
     {
-        $_types = Mage::getConfig()->getNode('global/payment/cc/types')->asArray();
+        $_types = Mage::getConfig()?->getNode('global/payment/cc/types');
+
+        if (!$_types instanceof Varien_Simplexml_Element) {
+            return [];
+        }
 
-        uasort($_types, ['Mage_Payment_Model_Config', 'compareCcTypes']);
+        $_types = $_types->asArray();
+
+        if (!is_array($_types)) {
+            return [];
+        }
+
+        uasort($_types, self::compareCcTypes(...));
 
         $types = [];
         foreach ($_types as $data) {
@@ -115,7 +129,7 @@ public function getCcTypes()
     /**
      * Retrieve list of months translation
      *
-     * @return array
+     * @return array<int, string>
      */
     public function getMonths()
     {
@@ -131,7 +145,7 @@ public function getMonths()
     /**
      * Retrieve array of available years
      *
-     * @return array
+     * @return array<int, int>
      */
     public function getYears()
     {
@@ -155,22 +169,6 @@ public function getYears()
      */
     public static function compareCcTypes($sortA, $sortB)
     {
-        if (!isset($sortA['order'])) {
-            $sortA['order'] = 0;
-        }
-
-        if (!isset($sortB['order'])) {
-            $sortB['order'] = 0;
-        }
-
-        if ($sortA['order'] == $sortB['order']) {
-            return 0;
-        }
-
-        if ($sortA['order'] > $sortB['order']) {
-            return 1;
-        }
-
-        return -1;
+        return ($sortA['order'] ?? 0) <=> ($sortB['order'] ?? 0);
     }
 }
diff --git a/app/code/core/Mage/Payment/Model/Method/Abstract.php b/app/code/core/Mage/Payment/Model/Method/Abstract.php
index a2a1b4bb658..42838917dce 100644
--- a/app/code/core/Mage/Payment/Model/Method/Abstract.php
+++ b/app/code/core/Mage/Payment/Model/Method/Abstract.php
@@ -805,4 +805,16 @@ public function debugData($debugData)
     {
         $this->_debug($debugData);
     }
+
+    /**
+     * @return int
+     */
+    public function getSortOrder()
+    {
+        if (!$this->hasData('sort_order')) {
+            $this->setData('sort_order', $this->getConfigData('sort_order'));
+        }
+
+        return $this->getDataByKey('sort_order');
+    }
 }
diff --git a/lib/Varien/Data/Collection/Db.php b/lib/Varien/Data/Collection/Db.php
index 1579d7ccc86..5eea149cde4 100644
--- a/lib/Varien/Data/Collection/Db.php
+++ b/lib/Varien/Data/Collection/Db.php
@@ -66,7 +66,7 @@ class Varien_Data_Collection_Db extends Varien_Data_Collection
     /**
      * Fields map for correlation names & real selected fields
      *
-     * @var null|array{fields: array<string, string>}
+     * @var null|array<string, array<string, string|Zend_Db_Expr>>
      */
     protected $_map = null;
 
@@ -899,7 +899,7 @@ public function addFilterToMap($filter, $alias, $group = 'fields')
     {
         if (is_null($this->_map)) {
             $this->_map = [$group => []];
-        } elseif (is_null($this->_map[$group])) {
+        } elseif (!array_key_exists($group, $this->_map)) {
             $this->_map[$group] = [];
         }
 
diff --git a/lib/Varien/Image/Adapter/Gd2.php b/lib/Varien/Image/Adapter/Gd2.php
index 3372fd43f27..44629e0d720 100644
--- a/lib/Varien/Image/Adapter/Gd2.php
+++ b/lib/Varien/Image/Adapter/Gd2.php
@@ -130,11 +130,11 @@ public function save($destination = null, $newName = null)
     {
         if (isset($destination) && isset($newName)) {
             $fileName = $destination . '/' . $newName;
-        } elseif (isset($destination) && !isset($newName)) {
+        } elseif (isset($destination)) {
             $info = pathinfo($destination);
             $fileName = $destination;
             $destination = $info['dirname'];
-        } elseif (!isset($destination) && isset($newName)) {
+        } elseif (isset($newName)) {
             $fileName = $this->_fileSrcPath . '/' . $newName;
         } else {
             $fileName = $this->_fileSrcPath . $this->_fileSrcName;