If you think there's no difference between a password and a passkey, that kind of tells me you don't really know a lot about passkeys, so it makes sense you'd think they're just worse-implemented passwords.
The only difference is that you sign the authentication.
I think Facebook does the same thing when logging in with a password.
It’s been crudely done for ages by sending over a hashed version of you password when submitting a form.
Not the exact thing, but still.
What is the problem they’re trying to solve? I’m not sure to be honest. Is it leaked passwords/keys? No difference there, as all passwords are unique anyway with a password manager.
Is it ease of use? I hoped so too.. but nope.
Is it anonymity? I hopes so too, but just like “hide-my-email”, apps will detect it, and require all other missing info such as your real email, name etc.
The only difference is that you sign the authentication, except all the other differences like the server doesn't keep a secret that can be stolen, it can't be phished, you can't reuse it, you can't mistype it, you can't store it improperly.