These are incorrect arguments - hunter-gatherer human societies were anarcho-syndicalists by obligation. Everyone needed to cooperate to survive. Early agricultural societies after agricultural revolution - same.
The priest-kings you speak of in Egypt and Sumer came to be from the officials of central granaries which organized storing of seeds, grain, and other types of produce and redistribution of them to those who deposited them there when needed. They were public warehouses, treasury organizations.
Actually, I have a reference on that topic that will knock the socks off of you all:
Egyptian Pharaohs had to justify their existence to the public even much later when the aristocracy was established, and the bar for being a good pharaoh was always 'I did these and other things. Egypt is much better now and Egyptians live better'.
The early Egyptian army was literally constituted by the gathering of Egyptians upon Pharaoh's call rather than the Pharaoh having a central army even.
...
So no. Dictatorship is not the default state of humanity. Actually, even selfishness is not the default state of humanity.
