That's an interesting point. Vending machines never became a big deal outside of Japan. Fast food was automated in 1964, with AMFare [1], but that was never deployed beyond one prototype.

Whether general purpose robots will change this is interesting. It looks like they're going to cost about as much as a car. (There are at least 18 makers of humanoid robots. The hardware situation looks good.) That's cheaper than humans. There are already companies that set up industrial robots and charge for them by the working hour, with all maintenance and setup included.

[1] https://www.youtube.com/watch?v=1Xop9py8zBY