The problem with tellers and checkers is... when i was young, these people seemed to be at least competent, today, they have problems operating a really simple user interface.
An interface that i could handle far easier, with less hassle, and i can get exactly what i want.
Today, it is like Wallymart has gone out of their way to higher the lowest IQ people they could get to run the registers. They aren't even good for chatting to.
Unfortunately, once these big stores replace all with robots, then all the people will disappear.
It will be like the stock market, when they went digital, everyone left the floor. It became a ghost town. The same will happen with stores and restaurants.