I think this is really great news and am glad to see FIDO move forward as I think it greatly increases account security. One aspect of FIDO that could still be troublesome is account recovery in case of inadvertent loss of passkey. OOB recovery with SMS or email is considered too weak and the main recommended alternatives are to maintain multiple authenticators (i.e. multiple copies of your passkeys), re-run onboardi…
I think the idea is that passkeys are synced between devices, see e.g.:
https://developer.apple.com/videos/play/wwdc2021/10106/
I haven't look deeply into passkey enough yet, but aren't we replacing "what if I lose by device" by "what if company XYZ decides to nuke my access to my synchronized passkey"?