My second point above contains the seeds of what you’re looking for: humans evolved culture which enables us to function in a wide variety of organizational styles across a large range of population sizes. Huge power imbalances, the most extreme being dictatorships, are not a barrier to human survival.
The fact that humans evolved in an environment without huge power imbalances is no more relevant than the fact that humans also evolved in an environment without huge temperature variations and yet are thriving on every continent save Antarctica (we could thrive even there but we have no reason to try). We are extremely good at surviving, even if we’re not always happy about it.