To touch on the feelings of FOH restaurant workers, I feel like we are slowly moving away from what we want as an experience in most fast and casual restaurants. I think the Chili's model someone up thread outlined where we order on a kiosk app and pick up the food at the window and we don't have high school kids messing up your order or going MIA or bothering you too much, is the way.
When I am going through a drive-thru, between the hours of 8a - 6p, I'm 99% of the time on a conference call, either passively participating or actively listening/talking. After I place my order, I don't want anything more than a quiet transaction of take my credit card and hand me the food. The same with the casual food places I haunt, and they've gotten used to me by now and I tip over the top so they know it's not personal, but at first it was like can't you see I'm busy, just take my order and leave me alone and please don't try and talk to me, I just need to eat.
You know how the Sprinkles in University Park has a cupcake ATM so you don't have to go inside? I think we need that for QSR and Casual Restaurants because people aren't going for a human experience, just for food and convenience. Automate that food wall, Mr. Gorbachev.
That said, there will always be a need for the upper end waitstaff and sommeliers and folks like that to serve guests who are looking for food experiences where the goal is to communicate and connect with other humans. Think of dinners with clients, business folks, family events, etc. where you aren't on your phone or it is rude to multi-task.