Humans are hierarchical by nature. The family is the first place where humans learn that there is a hierarchy & everyone is assigned his/her special place. Even a child's designated birth order is hierarchical as it establishes his/her specific place in the familial scheme of things.
Human societies are hierarchical. That is the natural order of things. There is a pecking order starting from the family which extended to the outer society. Hierarchies are established to determine who is dominant & who is weaker. The premise is that not all of us are equal. Nature doesn't work that way. There will be always those who have preeminence & dominance based upon their looks, intelligence, educational, & socioeconomic backgrounds. That is an undeniable fact of human existence. There is even a preeminent world in the natural i.e. animal & plant kingdom so why should the human kingdom be any different.
The preeminent & dominant classes want to ascertain that they & their descendants have the power which is why socioeconomic systems w/its rules & perks are established. The powerless & subordinate classes are the ones who follow the rules that those who are preeminent & dominant establish. Also, the powerless & subordinate classes have no say as to how things should be run. They are the classes who are owned while the preeminent & dominant classes OWN.