This could be a good long conversation to have. Not sure if HN is the best place and format for it, so I will keep it short.
> Hierarchical governance seems natural to us, pretty much written into fabric of social reality.
Hierarchies have existed for basically forever and it's almost always the natural state of organizations not just for humans. I wouldn't argue the opposite. What has changed and almost certainly will keep changing is the nature of these different hierarchies. Moreover, we have more than one single type of hierarchy co-existing. Just compare Switzerland to China in present time, or compare the independence of Hellenic city-states with the growing centralization of the EU and you will know what I mean.
The one thing that is recent (and IMO misguided and/or totalitarian) is the idea that we can organize ourselves into one single global hierarchy, an all-encompassing entity that would be able to subject all different countries into one unified set of rules. Some look at Europe and the EU as a way to show that would be a good thing, but completely ignore the fact that the EU it is not an unanimous organization. Libertarians think that all-out globalization and absolute free-flow of commerce will smooth out every international issue and will completely ignore the fact that this only works if every one is on similar level of individual freedom and economic development. Communists refuse to accept past failed attempts because in their view Communism can only work if the whole world adopts it.
Every Utopian project that requires every one to conform to one single set of rules has failed and will always fail due to the impossibility of satisfying the needs, values and wants of everyone at a global scale. I hope we can agree on that.
> Once a group reaches more than couple dozen members (...) you need to create a level of governance in order for the group to grow and stay coordinated.
Right, and the beauty of blockchain is precisely that it solves the Byzantine Generals Problem. You can have any number of people that don't know and don't trust each other able to coordinate without any central authority.
Granted, this is not a perfect solution. It's not like that just because we can have a computer network telling us "who controls X and who should have access to Y" that people will blindly follow it. You will still have groups trying to control things by force, abuse the system and so on. Societies will still have to have their military forces.
The key difference is that now these disparate people and societies no longer requires nation-states to organize themselves. People won't be forced to swear allegiance with to one tribe or another just because of the place they were born, etc.