I'd be on board with Passkeys if there's an open-source app to set, authenticate, back-up and restore passkeys between devices. I held off getting 2FA TOTP codes until I used andOTP.
...if you’re syncing passwords through a browser, a password manager, iCloud Keychain, or one of the Microsoft or Google equivalents, be aware that you are already trusting a cloud service
I don't trust and don't use any password manager services. I'm also wary of the single-device passkeys because I don't like having a single point-of-failure to access to my accounts. I know password/recovery options can be used as fallback, but my adoption of this new tech will depend on these factors.