Except they never considered that "complete idiots" could lose access to their phone's passkeys.

They did, that's why they sync

Right... just let me pull out my non-existent spare phone when mine breaks or gets lost.

It'll work if you have a laptop on the same account, iCloud or 1password or whatever else. If you only had a phone, you set the account up again on your new phone.

How does a person sync their passkeys between devices?