[Ferret7446]

I find that sentiment ironic because I won't use it unless it can't be backed up (the main selling point of 2FA and hardware keys).

If it can be backed up, then a casual bystander/process can also "back up", filch all of your credentials in a few moments with you being none the wiser.

The protocol is open, so I can use one proprietary key from company A, one from company B, and a few open source keys. Keep one for regular use and the rest as backups.