So one of the problems with password is that users reuse them or use some weak password. For the latter, even enforcing pattern does not work as users will simply go for something like P@ssw0rd1 that is easy to guess.
So instead of a user or email and password login, why not a pin and password? The pin will be generated during sign up (It can be as complex as the webmaster makes it to be and not necessarily a 6 digit pin like your bank card).
This way, even if the user decides to make a simple password, the account will always be protected by a secure and unique passphrase whether the user likes it or not.