What I find interesting about the Culture as a literary and philosophical concept is that it forces you to choose whether material superabundance and unrestricted freedom is enough to be happy.

Right now with our current civilization we still need to work and have at least some restrictive social structures, because distribution of scarce resources is still a thing; working within these constraints is where all contemporary culture and politics comes from. So at the moment it's still possible to "dodge the question" (although less and less so as time goes on), but once you have the Culture you can no longer do so. You have to choose if you can be happy inside the system of unlimited freedom where you can choose total hedonism or try to construct some kind of meaning for yourself, or if you will "go Horza" and demand deliberately worse social structures to try and force the meaning back in from without (note one of the other comments in this thread saying "the Idirans were right").