The idea that humans are fundamentally hierarchical and competitive creatures is just wrong. Of any indiviual trait could be said to be the character of humanity it would almost certainly be cooperation. Practically every hierarchy that humans lives takes a ton of organized forced to uphold, specifically because living in hierarchy is not natural for humans.
Libertarianism original referd to anarchism actually. The modern usage of ultra-capitalist nonsense comes from people intentionally redefining the word cause they were mad that Liberalism no longer referd to what they were doing