You forgot something, of course, not that important at all. Because of the expansion of the population and less food being produced, the price will elevate, of course, till a certain point, and here comes the bot problem. The bots don't produce the food (taking your exemple), it's true, but they generate the money (lot of then) that is used to buy food, and they """"give"""" it to the people that want the food. Now, we have more people that want the food, less food to supply the damand and more money and extra money to buy the food. The price that will grow will be more higher because of the extra money produced by the bots.