I think you have a point and a decentralized system will only stay decentralized if it has practices and norms that actively combat the natural development of hierarchies. This is generally what we see in non-hierarchical forager societies which are generally the most successful examples we know of at putting these principles into practice. But at least historically, these societies have not been as successful at combatting hierarchical violence by outsiders. For this reason I think a larger real world anarchistic society cannot necessarily pursue maximum human freedom without considering economic efficiency, organized self-defense, etc. How to develop such institutions and practices without hierarchy is a largely unsolved question, and it may be necessary to learn by trial and error.