> that passkey will also be available on your other Apple devices if they are signed in to the same iCloud account
I am not sure I like this. Unless the passkeys are only transferred directly device-to-device, each OS vendor's user cloud storage now becomes the keys-to-every-kingdom uber-target.
If that is a concern of yours, there is an option on Apple devices to disable iCloud syncing for passwords/credentials. This would limit passkeys to strictly device-only.
> Passkeys on iPhone require that you use iCloud Keychain. If you don’t have iCloud Keychain turned on when you try to save a passkey, you’ll be asked to turn it on.
I am not sure I like this. Unless the passkeys are only transferred directly device-to-device, each OS vendor's user cloud storage now becomes the keys-to-every-kingdom uber-target.