Just thinking that if a defenseless woman gets robbed, the robber only has to grab her phone and force the woman to look at it to open a device that may very well have her entire life in it. Information involving her finances and her family could be taken away from her easily. Therefore, I believe facial recognition will start a new wave of crimes.
The rumor is that FaceID isn't just a one-time deal, but continually needs confirmation that the person using the device is you.
So, you will be able to unlock your phone, then open your banking app, and then hand it to someone to view. But, if someone mugs you, holds the phone up to your face, unlocks it, and then runs, your phone will not let them open any additional apps that are listed as possibly containing personal data.
So, he won't be able to get into your banking app, contacts, calendar, notes w/passwords, etc, because his face will not be authorized to open those apps. Therefore, the theory is, FaceID will be more secure than TouchID.
We'll have to see if this works in reality, but I'm pretty excited for it.