I wonder how true that is. It used to be that 90%+ of citizens were employed in agriculture. Your hypothesis is that we switched from replacing all those farm

I wonder how true that is. It used to be that 90%+ of citizens were employed in agriculture. Your hypothesis is that we switched from replacing all those farmers with "even more" factory workers building farming machines. This seems like an extraordinary claim. If one tractor replaces 10 farmers, why would you need 10 workers, full-time, to build this one tractor? It seems much more likely that the slow disappearance of all those farming "jobs" was, kind-of coincidentally, timed with the need for building cars, clothing factories etc.