Anthropology

First it's rodents carrying disease. Then it's a restricted diet, when that clearly wouldn't have been the case. I know of no farmers this century or centuries ago who would not have had a varied diet and found ways to preserve foods from all seasons. Since when would farmers not have had access to all the same things the hunter-gatherers did? Smoked fish? Smoked and live caught meats? Preserved and gathered berries, other fruits and veg?

B) the skeletal remains "studied" are not an inclusive subset of all cultures over all times. It's the few skeletons that actually survive and are preserved through a fluke of circumstances, often improved by larger societies made possible by the support of intentional cultivation of foodstuffs. It's not even as good a sample set as political polling right now and that's shite.

C) diseases, including childhood diseases have been around since before agriculture changed societies - which all happened at various times in different locations/continents.

D) animals bringing disease and sharing it with human communities is certainly a contributory factor to mortality and morbidity rates, but I sincerely doubt that a significant percentage of death from parasites, animal injuries, and contagion appeared by consuming a domesticated cow/sheep/horse/pig than those harvested from the wild in circumstances that were far more likely to result in the death of the hunter or hunters.

E) Neolithic, bronze age and iron age cultures lived in small groups, whether hunter-gathers, agriculture focused, or mixed sustenance cultures. The diseases they would have died from would not likely be the kind shared from person to person, but more likely from insect/animal to person or nutrition based. Sanitation is always an issue with fixed housing. Some Native American groups farmed in one season but kept their movements about the region as they had previously to harvest wild plants, seeds, berries, etc. I have no idea why anyone would assume that early ag development in Europe or other continents would have been different.

Agriculture didn't all of a sudden make people dumb. The old ways didn't die. It wasn't an either/or; it was a both/and. But I'm getting the sense that we'll have to agree to disagree.