We had originally planned to go all-in on passkeys for ONCE/Campfire, and we built the early authentication system entirely around that. It was not a simple setup! Handling passkeys properly is surprisingly complicated on the backend, but we got it done. Unfortunately, the user experience kinda sucked, so we ended up ripping it all out...
Bitwarden just announced a consortium with Apple, Google, 1Password, etc to create a secure import/export format for credentials; spurred by the need for passkeys to be portable between password managers (but also works for passwords/other credential types)
Import export is not the same as interoperability
The interoperability already exists in the protocol webauthn, part of FIDO2 which has been around for almost a decade. Interoperability is not remotely an issue with passkeys. Imported/export is/was and also already has a solution in the works.
I’m definitely holding off on passkeys until that project is finished. I also don’t want vendor lock in and while that seems like the solution, it seems like they just started working on it.