> How on earth are the big players introducing this when we can't even back up the keys?

> Another things is I "lost access" to passkeys.io while trying out passkeys. My phones Bluetooth was switched off, and by the time my phone created and saved a passkey, it timed out on the computer. So now I can't login with that passkey and it only fails. Seems like I'm locked out now...

What does "backing up" the key achieve over and above just registering another key?