Hierarchy. Don't get me wrong, I don't mind that people have different responsibilities, and I don't mind that it may mean, at work, for example, that people have the power to override my decisions, or even terminate my involvement with some endeavor. Distribution of responsibility is a key belief of mine in all system design.
But Hierarchy is different. Everyone probably knows it means you have a boss, that your boss has a boss. and it travels up like that to the top somewhere. Perhaps there is even a commitee at the top, but of course this in general has a Chairman who is The Boss. It does mean there is ultimately one boss of everything, But it means more than that. Let me explain what it's about in terms you might not have considered.
Hierarchy is based on a metaphor of the roman arch. The roman arch is a curved arch with a single stone at the very apex and center.
This metaphor, and this particular idea of Hierarchical organization is essentially used to control modern society, and although we have democracy now it's no different than before, people have always had the power, and this is apparent from the top of the arch. The arch is an elegant metaphor for the appraoch.
The force gravity represent the "real" or "hard" labor of the arch. At the base you have stone holding the entire weight of the arch, and as you go higher and higher the stones feel less of this weight. Instead they feel an increasing lateral tension, the back and forth forces in the arch until the keystone. At the keystone nothing is being supported in the direction of the force of gravity which would pull the whole thing down. The left and right legs of the arch being curved would of course tend to topple. By arranging them so they oppose one another, the keystone is able to support a far lesser pressure at either edge than what gravity offers the lower stones, but it also gets to feel that by holding these forces in ballance it keep the arch up. Remove this one stone and the arch collapses!
But come to think of it, remove any stone at all from the arch and it collapses. This is generally beyond where the methaphor is taken.
This is a design metaphor, like a software engineer using the metaphor of a piece of paper for a word processor. That is, it's practical, it works, it's a working system. Other systems would also work, that is, function, with different characteristics of course. But this system works and is the system that has held republics together for some time.
It's too simple and too centralized for much more modern use, that's all.