For biometrics in general, there's a huge list, starting from cannot change and therefore rely on the implementation, all the way down to hard to deny that I have access. While I can say, no, I don't have a password to this random device you are showing me, with biometrics, you can just wave it in front of my face and it unlocks. Maybe even when I am asleep / unconscious.

For the specific case here, about my laptop: for instance, I can't simply hand the notebook to my dad, _telling_ him the password and he's good to go. This is the downside where I can't simply share a (biometric) login, even if I want to. Which also means that every access automatically implies that it's really me, and not someone else I just gave quick access to without reconfiguring the system.