Once people have certain comfort they cease to be productive and look for ways to while away their time. Sometimes its neutral, sometimes it may be a productive hobby and sometimes it's detrimental (as in they know what needs to change in the world and they will make it so).
It's also telling that at the dawn of the XX cent, the US was not a wealthy country. Per capita we were more or less on par with countries that are today still "developing". Out position isn't a foregone conclusion and needs active development to remain there.