Yeah, there needs to be a way to link password managers to share passkeys, and also to share passkeys between people. There are also a lot of great features that could be implemented with passkey sharing too, like revocation, time limits, or capability limits.

Adding the kind of sharing it sounds like you are describing would just shift the attacks to that new attack surface. The attackers would basically try to trigger and intercept those shares.

If machines, browsers, phones etc are set up properly (yes, I know, big ask, especially with the confusion surrounding this, so I acknowledge the caveat), then the vast majority of passkey requests will go right into the preferred method (i.e. 1Password, Bitwarden, even Apple, browser of choice, etc). And most of those now will allow that passkey then to be used on a different device if signed in and synced.

I have found it to work pretty well with a password manager. I would suspect OS level passkeys would be much less "portable", especially across different manufacturer devices, like Mac/Windows, or even Windows/Android, etc. Which is why I waited to start using passkeys until I could use a password manager to store them, and I turned off all other passkey storages (same as I did for password storage before).