It hurts a lot more to change your face than to change your passcode
Why you shouldn’t unlock your phone with your face
Quincy Larson

One quick comment that popped in my mind when reading this. I have a beard, thick enough that even my wife didn’t recognize me on the one occasion she’s seen me clean shaved. It seems like one way to change your password (assuming you can grow a beard/moustache, or you can just use a fake one). But at the same time it could lock you out of your phone if you shave and FaceId doesn’t recognize you anymore.