Except at the time “farmers will be broke” would have meant “everyone will be broke” because most of the labor force was farming. Instead, farmers became a tiny part of the economy while food became increasingly abundant. Tractors were a good thing, on balance. The commenter is saying that a similar shift will happen.

I tend to think that if alignment can be solved, AI will improve the wellbeing of humanity in a way nothing ever has. But I don’t know if we can solve alignment and it might kill us all.