Speaking as a U.S. citizen, I think the problem should not be approached as "stop people from doing frivolous things", but rather "government should fund the commons". Of course this doesn't make government perfect, but generally it appears to be the most successful way to achieve things like caring for the elderly and disabled, building monuments, protecting wild areas, etc. Turns out we do all these things to some extent, just not as much as some (myself included) might like.

Which is to say, a well run society should have room for BOTH frivolity AND supporting the general welfare of its people. Perhaps our current troubles are the result of many people thinking that supporting the general welfare IS frivolous.