As far as I can tell, the reason hierarchy and elites are prevalent everywhere is not because they make a system more efficient- it’s because they make a system more expansionist and violent. When you put someone in a position of power, insulate them from the consequences of violence, and give to them all the benefits of violence, you get a more aggressive and expansionist society. So over time the peaceful egalitarian cultures just happily exist and the violent hierarchies attack all their neighbors, and guess which one tends to predominate.
