Could you explain how this holds for monarchies? The succession of power was mostly based on blood relations and frequently brought along major changes to existing power dynamics. Meanwhile the majority of the population was barred from gaining any real economical or political power, aside from very few cases.
As far as I can see, greed isn't automatically the biggest determining factor in such systems. It can be, but I'd need to read convincing studies by historians to believe you on this.
The monarch who's greediest gets to keep the power, otherwise they'd be overthrown or lessened by their nobles. See the shogun taking power away from the emperor; King John signed Magna Carta ceding more power to his nobles under threat of force; various executions of monarchs over civilizational history.
That is to say, it's not always a monarch versus their general, oftentimes peasant, populace, it's rich and powerful people against other rich and powerful people.
No, the greediest monarch is the most likely to get assassinated, because they take too much from their nobles and everyone else. All the money in the world doesn't help a noble who is so greedy they piss off all their potential allies, or all their peasants. And if you were a noble who overthrew a monarch - with familial ties to enough influential nobles - because someone else has more money, you'd still be dead in all likelihood. And so on and so on.
All these relationships were incredibly important to the power dynamics, and you don't get to redefine "greedy" as "greedy, except those who are too greedy to properly play the political game". Greedy monarchs didn't last, and the greediest non-monarch-rich were unlikely to have enough allies to become dangerous.
I'm talking about generally greedy, all else equal, where one who lusts for power is more likely to obtain it than one who does not, not necessarily specifically the greediest which I agree with you others will tire of quickly.
