Are banks legally required to perform AML and KYC checks when opening new accounts?

Absolutely. Anti-Money Laundering (AML) checks and Know Your Customer (KYC) or Know Your Business (KYB) checks are now a standard part of any account opening process. You might not be able to see what is happening, but on the backend/back office all efforts are being made to identify you and the risk you may pose to the institution.

When I cite that it is a standard feature, it is not optional but rather mandatory.