Suffix adds additional information about customers. It is useful to show the general designation of a person such as "Jr." and "Sr.".
Magento 2 allows the merchants to enable or disable the suffix field in customer account in Magento 2.
Include or remove suffix field in the registration form, checkout and when adding new address from "My Account" section in Magento 2 store.
Check the method to show suffix field in Magento 2