This is a big one. Lock-in and the threat of provider blacklisting means it will remain a shortcut like SSO (“sign in with ____”) until we’ve established federated providers.

On further reading, this may not be as far off as I thought. Passkey registration providers can be OS-level but browser and password manager based solutions were intended (overview from FIDO alliance). And it looks like KeePassXC has begun rollout of their own. If I’m reading correctly they currently “piggyback” off of an OS-based provider in various ways, so it’s not yet an end-to-end implementation, but these are early days.