Yah - people get fooled by the drop in the relative percentage of the population when the absolute numbers are not actually changing that much. What is real is that the structure of overall society does change - food production becomes less of a concern and people shift their focus to producing other things - but it's wrong to imagine that food production is less important. It just becomes relatively well optimized and less economically productive (i.e. lower ROI for capital). You still need the food just as much.