Here is another view: some of them maybe do things to perform richness. And others are probably so bored that they just try new extreme things, but nothing fills that inner void. I can't get no satisfaction.
Most people find work that directly addresses their basic needs fulfilling to some degree. Things like growing your own food, hunting, building and maintaining your home, etc.
and they can still do that if food is available for free. in fact people today put enormous amounts of effort into growing their own "organic" food instead of buying the cheap stuff from supermarkets. I don't see why that wouldn't still do it when it's essentially free.
Or maybe not. I'll never know.