Why? The human species and relatives have organized into heirarchies since their dawn.

You start as a child, and go forth and develop your place in the world.

If everyone is the same, no one is unique.

Different desires lead to different contributions which have different levels of value to society which lead to different levels of social status.

We've also killed each other since time immemorial, doesn't mean we have to like it.

No one wants to not be on top, but being on top doesn't maximize everyone's happiness or sense of purpose either.

If true, that would make it even more cool.

You’d have to venture outside of our planet to find such a thing, and even then I doubt you’ll find what you’re looking for.