Why do you say this? Hierarchical organization provides coordination of action that yields massively non-zero-sum outcomes compared to uncoordinated systems. Within this framework, yes, if one person gets promoted then another does not (though there's even a bit of flexibility there in most hierarchies save at the very top). But hierarchies scale, and scale is extremely important.

The critical task of political philosophy and similar intellectual endeavors has been to maintain the massive advantage of synergistic coordinated action while nonetheless curbing abuses and appealing as much as possible to our instincts (which aren't ideally suited to such things).

That some hunter-gatherer societies can operate on a self-motivated egalitarian basis with ad-hoc leadership is hardly a compelling point when the tasks required in a hunter-gatherer lifestyle are so dissimilar to what is required to maintain an advanced civilization. At best, it is a motivation to explore alternatives to see if they can be made to scale and what problems arise with scaling, not a demonstration that an alternative is superior.