The protocol is private key stored on your hardware; public on the service you're authing to. Google doesn't have a way to MITM that, but if you lose the machine storing the private key, best have another way to auth.
(Note: some implementations, including Chrome on Android, do allow sync and sharing of the key, but IIUC even if Google bars you access to your account, the phone will still have the private key and can still do the login).
well, the argument is that for strong passwords you will need to use a password manager anyway. Which you will sync somehow, which will sync your passkeys too. So in the end you might as well replace all your passwords with passkeys except for the one password you use to access your passkeys in your password manager / the master access basically. The one way to make sure that you never lose access. I think this makes sense, I'm also very dependent on a password manager now.
Yes, the hardware vendor that controls the kernel and chips can do whatever they want. I meant there is no method as per the definition of the protocol to MITM the passkey because the device only ever emits the public key unencrypted.
The protocol is private key stored on your hardware; public on the service you're authing to. Google doesn't have a way to MITM that, but if you lose the machine storing the private key, best have another way to auth.
(Note: some implementations, including Chrome on Android, do allow sync and sharing of the key, but IIUC even if Google bars you access to your account, the phone will still have the private key and can still do the login).