Passwords can be secure when the end user picks a strong one. But that is the biggest problem with them, the end user. They don't pick good passwords and decades have shown us the general public are bad at passwords.
Passkeys are not biometrics. They are much simpler. In a very simple way you can think of them as a secure long random password that is stored on you device, generated per device, and not sent over the wire to the other side (so more like public/private key cryptography I believe).
The passkey on your device can be stored in an encrypted vault or even secure hardware that requires a pin/password or key to unlock.
They are not getting rid of multifactor codes and can be used with them. But by protecting them locally you can still have 2 factors to access them - the hardware/vault that contains them and the pin/password/biometric that unlocks the vault. And that is in addition to server side multifactor systems.
But even without all that you still gain massive benefits over passwords as it stops cross site comprises when one sites gets their password database leaked. Or brute forcing access to systems by guessing weak passwords that most people use.
I personally hate global menu bars. They do not work with focus follows mouse. The way menus currently work is fine for me and I would not want to lose that to, IMO, a much worst system. Any global menu implementation would need to be able to be disabled and better to have it off by default. And I would rather see effort in developing other features personally - though mostly as I would never use this feature.