It sounds like people’s biggest knock against passkeys is that where they are stored is siloed to the Apple or Android ecosystem, so when a user changes platforms, they have a hard time accessing. 

This seems fairly edge case, solvable via a migration tool, and not a good enough reason to lose the ease of passkeys.

Passkeys can be default saved to your 1Password very easily, so they are already cross device and cross ecosystem.

passkeys have made my life infinitely easier and i like using my yubikey