That’s likely true. But it’s hard to imagine that anyone who would log in with the system that you propose don’t know what a password manager is. I’ve been using a password manager for a decade or so, have multiple fido keys, use Google authenticator, and don’t quite understand what you propose.
It seems improbable that such a system will be added unless at least a few enterprise customers want it. I think it’s on the order of at least 50 hours work for someone who knows a lot about the authentication system, and likely twice that with proper specs. There was an attempt a while ago to integrate with keybase, which could do some of what you want, but I don’t think it got very far.
It’s an interesting idea,though. Maybe it’s easier than I think.