One idea that stuck with me is that shit zoos have concrete cages for the monkeys, and they're miserable in them, showing similar signs to modern humans (depression, addition, anger), whereas nice zoos try to keep the monkeys in similar environments to those that they evolved for, where the monkeys are pretty much chill. The author argues that we're constructing concrete zoos for ourselves and in the process making ourselves miserable. We're so far detached from what our bodies and minds evolved for, that it's an alien environment for our species.
If this holds truth, it's really no wonder that the more we pile on and the further we stray from our true species' preferences, the more horrible we will feel, and this hikikomori is a fine illustration of that.
As some comments pointed out 'what about the great depression', 'what about 'nuclear war', "don't you like your electricity"? These are all human patches for human made problems. I don't think the correlation between progress and wellbeing is as clear cut as some would like to see it.
[0] https://www.amazon.com/Civilized-Death-What-Lost-Modernity/d...