Hardware keys are the way:
- Less likely to fail in the first place
- Cheap enough to have several of so you can use one to log in and manage the others in the event of loss
- Easy to move between devices
- Less likely to use the auth handshake as a side channel for things you didn't consent to
My non hardware key is a keypass file that I update only on my laptop and I sync to my other devices. I have plenty of backups. It does also the TOTP required to login into some customers servers.
I keep all my TOTP keys on an encrypted usb drive in a safe. When I lose a key, I manually add all the TOTP accounts onto the new key from my safe
Passkeys are a different story. Every account I need to make sure I have multiple yubikeys registered. When I lose one, I get in via a second key and then add the replacement one.
It’s a pain but it’s a model that makes sense to me. Lose the key? Time to reach for my backup key.