McDonald’s already has almost completely automated restaurants. Just one or two people to maintain the machines and load raw material. It’s been running in Texas for about a year.
I tried to find more information about this and I only saw a location where the drive-thru was automated. I think it would be very difficult for McDonalds to automate the food preparation and assembly steps, given the current state of the art in robotic manipulation.
26 years ago or so I dated someone who worked in a McDonalds that had a prototype robotic drink filler. It worked great except sometimes it would dispense random drinks.
It was driven by a really long RS232 cable from a computer in the back, and the random behavior coincided with starting some motor...
It seemed like it would be an easy fix-- toss in RS-485 converters, or change the communication protocol to be robust to corruption-- but instead it ended up disabled most of the time when it would clog itself up with bogus dispenses. I believe it was regarded as a failure.