Right, hierarchies are a necessary tool for managing complex systems. Hence why they continue to show up both in nature and human organizations. They're not some inherent evil as anarchists see them, but merely a tool for creating abstractions and partitioning work. At this point, I'm convinced that anarchism has been sanctioned and promoted as a legitimate form of dissent within the western system precisely because of its opposition to hierarchies. It ensures that anarchist movements never actually grow and become a genuine threat to centralized state power.