[Scion9066]

Generally attestation is not supported outside of enterprise contexts and Apple for example doesn't support it without mobile device management policies being applied to the device.

You can make your own backups of passkeys from your password manager.

I believe you are confusing ones that are stored in software or syncable (Passkeys) with the hardware backed credentials (platform authenticators).

[josephcsible]

> I believe you are confusing ones that are stored in software or syncable (Passkeys) with the hardware backed credentials (platform authenticators).

The problem is that the protocol allows websites to require use of the latter. If the two were indistinguishable to the website, then passkeys would be a good thing.