> Or a hundred more $100+ millionaires who aren't preppers?

This.

I live in Wyoming and frequent the Bay Area, New York and some places in Europe and India. The rich preppers are rare. (And mostly techies or oil men.) It’s mostly a middle-class pursuit, the singler and older and maler the person, the more likely they own clothing in camo. If they’ve spent any time in a military or intelligence service, their “prepping” is basic emergency preparedness, not bunker lunacy. (Though one retired special ops guy who started military contracting kept a map of the bunkers. I think as a joke. The saying being a well-stocked bunker owned by an asshole is a good target for a group of guys with guns.)

At the end of the day, the rich preppers build bunkers because it gives them something interesting to talk about. That group is mostly chasing that high.