I know this response is a little tongue in cheek, but you make a good point regarding entertainment. It seems like passive entertainment is a sort of sponge of energy and attention in a society. At a certain size, that probably helps keep things organized, but if that option is not available, the group has to come up with elaborate ways to expend that excess energy.

Once all the survival tasks are done, you really don’t want a bunch of military-age males standing around listless without direction. I think this was part of the pressure that gave way to elaborate rituals, construction projects, exploration, etc.