It's all about the FIDO2 hardware attestation. I'd rather use a FIDO2 authenticator with attestation. Call it a passkey or not, I don't want the to use the syncable passkeys without hardware attestation.
But it's a bad thing for self hosters anyway. Because parties will make exclusive deals or only wish to deal with authenticators they trust (eg that pay them for 'certification')
Some companies are comfortable with the idea of a two-factor method that can be airdropped to friends. Major organizations (AWS, among others) are not huge fans of passkeys for enterprise use. When passkeys released, our initial response at AWS was to give organization admins the ability to disallow passkeys.
Overall, I think there are fixes coming across the board from Apple and the FIDO Alliance to address some of the early shortfalls of passkeys.
They can provide the total hardware package for their employees to sign in with anyway.