> Imagine having to use a specific password for each service/device combination. Instead we don’t tie passwords to devices, but to users, to avoid this complexity.

But that is the entire premise of Passkeys—they remove the complexity, because having individual passwords per device is clearly superior to user-bound passwords, if you don’t need to worry about it and it just works. Hence why, to stay with SSH, you shouldn’t use SSH keypairs, but certificates signed by a CA.