>Will people with something important to hide still wear disguises? I'd bet yes.

Facial recognition systems can be (and are) trained to not be fooled by things like facial hair, hair changing, eyeglasses and sunglasses, hats, etc. Although it can obscure your features for sure.

If someone does something really odd to try to avoid the facial recognition (I've people posting things like making your hair non-symmetrical, or just avoiding the camera in the first place) then they just train on those things too. And that person gets flagged as being really suspicious. And things like full face masks are banned in some places already.