Hierarchies are heavily part of human behavior. The concept of leaders and rank is so ingrained in behavior it's hard to think it didn't exist even in hunter and gatherer societies.
Right now we have enough wealth such that everyone can live comfortably. But a lot of people still fight tooth and nail in the rat race all for what? For wealth partly but mostly for Rank. The higher your rank the better it's a huge driving force emotionally... especially for men. Desire for high rank is an inborn biological instinct. This is confirmed in psychology across all cultures. All men are emotionally more satisfied the higher their rank.
For women it's also a huge driving force for mate selection. Women marry up. They have a strong desire to marry the highest ranking man.
I would imagine in hunter and gather societies rank is maintained by two things. Brute force and social proof. Bigger men have more brute force to maintain leadership (hence why a lot of women are attracted to height) and social proof and respect insures that other men trust you and are more likely to listen to you.
That being said coercion to build things like pyramids or grand multi-year projects of vast scale requires someone to own wealth. This type of serfdom like heirarchy is much stronger then the hierarchies that existed in hunterer gatherer societies. Definitely more stable since wages and survival required someone to stay at their hierarchical post.
Either way hierarchies DID exist in hunter gatherer societies. It's just the tribe leader doesn't have enough power to coerce all men into building a pyramid. That being said I believe the article is disputing this part of what I'm saying but I don't think hierarchies are disputed.