In Langdon Winner's essay, Do Artifacts Have Politics?, she brings up the thought experiment of a ship. Ships need captains, and thus the ship's politics are inherently hierarchical. Likewise, many human endeavors require groups, which require leaders, which again, leads to hierarchy.
Leadership is a position of power, which attracts the selfish. A species could be inherently unselfish and still have leaders, though. You could have a species or environment where there's so much abundance that social penalties for being selfish outweigh the benefits.
Most species have selfish individuals, and most species have groups, and yet they don't develop complex hierarchies the way humans do. There is no need for them to build ships and extract resources that require seafaring. Human endeavors require groups because the value we seek is extraordinary. (See: Unbounded Value Needs)