The idea that facial recognition was just to determine if someone is in front of the machine is a diversion. A simple occupancy sensor would do the same, cheaper and more simply. The company only invested in the facial recognition because they are getting some other gain from it (presumably, data harvesting).
People have options, and it’s very easy to go somewhere else. If the food isn’t better the price and demand are going to be perfectly related. Every price hike matched by a corresponding drop in sales. Zero sum game.