While this is a very interesting and insightful article, it might be useful to add a broader historical/anthropological perspective. I'm not qualified to do that. But it's my understanding that development of agriculture and animal husbandry, and much later industrialization, drove huge increases in human population.

In part, of course, that was driven by the abundance of food and so on. But there was also the need for workers. So as machines displace workers, one might expect human population to gradually decrease, perhaps back to neolithic levels.

The challenge, then, would be to have that occur as humanely as possible.