I could see that. I’ve only found a few in the wild (mostly just enterprise, niche tech-related, and big platform web apps) but there’s probably some clunky implementations out there I haven’t suffered through yet.

For one, there seems to be this idea that if you lose your passkey you get locked out of your account forever.

True, plenty in this thread even. IIRC there’s usually a recovery key process same as a typical authenticator MFA, sometimes other routes in addition like combining multiple other MFAs or recovery contact assignment. Regardless, completely losing PW manager access across devices would presumably be the more immediate crisis for most.