[justsomeadvice0]

> doing basic entropy checks on a user-provided password pretty much solves the issue anyways.

No it does not. Users will find one high-enough-entropy variant of their password, and reuse it across all sites for life.

> Authentication is pretty much a solved problem

Hrm. It might be solved for you and users like you - but it depends on your site's demographics: most internet users on the whole will not know anything about encrypted "password lockers" and "physical Webauthn tokens". Browser-managed passkeys, on the other hand, stand some chance of being easy enough to use while enforcing good security and high entropy secrets, but lack widespread adoption so far.