From my understanding, humans barely scraped by for long time in the beginning. When did we get past the point of growing/hunting just to be able to be fed and get the point of offering to prepare a meal for someone else in exchange for something?
More contributions are always welcome and I suspect it isn't quite getting to the thrust of your question but the FAQ's Daily Life -> Food -> Restaurants section has this answer that you might find satisfying.
How long have restaurants been a thing? by /u/dhmontgomery, with follow-ups by /u/rkiga and /u/lord_mayor_of_reddit