The problem is: these more stratified, more complex societies are in essence Kleptocracies [hyperlink] where those in power redistribute societal wealth to themselves. Those at the bottom of the societys pyramid accept this unequal, non-egalitarian state of affairs because they too benefit from their societys relative advancement. Its a case of a rising tide lifting all boats.
Diamond says the Kleptocrats maintain power using 4 different methods:
1. Disarm the populace, and arm the elite.
2. Make the masses happy by redistributing much of the tribute, in popular ways.
3. Use the monopoly of force to promote happiness, by maintaining public order and curbing violence. This is potentially a big and underappreciated advantage of centralized societies over noncentralized ones.
4. The remaining way for kleptocrats to gain public support is to construct an ideology or religion justifying kleptocracy.
The obvious corollary of this theory is that most successful modern societies [hyperlink] are, in fact, kleptocracies. The key is to use the four methods to gain popular support in order to redistribute as much wealth to the ruling class as the populace will support. If the ruling class takes too much, it will be overthrown by a new ruling class (whichll do ditto).
So, is the US a kleptocracy Of course, it is! Is that bad Well, it depends on who you are in society, and whether the kleptocracy is efficient and fair over the long term.