If you remove a payment method in Magento 2 you will be unable to view orders which have been placed using that payment method in the admin and customer dashboard.
The error logs will show a message similar to the below:
[2020-01-23 10:27:34] main.CRITICAL: Class Magenest\Stripe\Model\StripePaymentMethod does not exist {"exception":"[object] (ReflectionException(code: -1): Class Magenest\\Stripe\\Model
StripePaymentMethod does not exist at /var/www/vhosts/some_customer/vendor/magento/framework/Code/Reader/ClassReader.php:19