The book that explains the billionaire doomers

They are mostly rich. And the problem when you become rich is that you have a lot more to lose. They become obsessed with not losing their wealth. This eventually evolves into a general doomerism. A miserable existence.

See Gollum.

Also "The things you own end up owning you" from the The Fight Club.

It's easier to fantasize about civilization collapsing than to put in the hard work to build and maintain community cohesion, and as you're busy fantasizing the collapse, you're not meeting people with different opinions and broadening your horizons.