Passkeys are just passwords that require a password manager; you can't login to a password manager without something outside the password manager, usually a password. (That's why they call it "LassPass" and "1Password"; there's one last password you'll still have to maintain.)
No password manager tries to get you to login with a passkey without setting a password, for precisely that reason. Apple, Google, and Microsoft do invite you to login to their password managers via passkey, because it's convenient and unphishable, but they always also allow you to login via password (or "backup codes", which are just backup passwords).
What if the robber hits you in the head and you get brain damage and forget your password?
I had more trouble with a failed 2FA than with a password.
Or straight up betrays you (you slighted them at some family event)