Complain loudly on Twitter and hope your tweet goes viral.
Apple account recovery supports setting a recovery code or having a friend listed as a recovery contact.
Apple does not yet support Passkey for iCloud accounts login.
I use a yubikey. But AFAIK, Apple doesn't actually use passkeys for iCloud/Apple ID authentication.
Not yet, but Google wants them to become ubiquitous. So in that (far) future, backing your passkeys up in a cloud (that is also protected by passkeys) doesn't help