but at a cost

Your claim was that it "remains to be seen" (whether agriculture turned out pretty well). I don't think it stands. Everything has a cost.

I am aware of the Jared Diamond arguments, but note that they are based on comparison between ancient hunter-gatherers and ancient farmers. Contemporary agriculture is a wee bit different -- in particular, note the diversity of food it provides, as well as its ability to deliver food out of local season.