> Same as traditional physical keys, you don't have a single key, you have multiple ones [...]

I have multiple identical ones.

> [...] and can go to the local locksmith and get another one in minutes.

Can I go to the digital equivalent of a locksmith (like a backup software) and duplicate my passkey? Can I do that with only my passkey in hand (without having to do anything to the corresponding lock, or having to contact its issuer), like I recently did with a physical key?

Heh, in the security world, this shows how your traditional metal key is "something you know" (like a password) because it can be copied and many people can know it at once!

So if we are enforcing MFA requirements and allow this kind of clonable key, then we should really require some other factor that is not clonable.

That's the core silliness of this whole passkey mess, IMHO. So many turns of rhetoric and weird compromises, we have cargo cult security and no real understanding of what security level is in place.

Instead of the best of worlds, we can accidentally have the worst of worlds without realizing until it is too late and we're painted into one of those ugly corners.