The main takeaway is this.
Agriculture was adopted as a system to increase population as a force multiplier. To an agricultural society more people is better. This is not necessarily so for a hunter/gatherer society. They have a social structure that is designed to sustain a static number of people indefinitely. This population doesn't increase unless something occurs in the natural world that affords them a larger food supply.
This is why HG society is stable, and also why the agricultural society's world is facing overpopulation and the inevitable food shortages that will occur when industrial farming collapses. The natural world can't support our numbers, we have to use tricks like using stored energy in hydrocarbons to make up the shortfall.
Agricultural society is a baby-making system, by design. That's why the religions/social mores of agricultural society are horrified by the idea of infanticide and euthanasia, practices which are common in HG society's.