You've posted here many points I'd agree with, but check the Ancient Egypt's economy. The key to their prosperity were their irrigation channels and constructing them required nation-wide labour mobilisation. Therefore the arable land belonged either to the king, or to a temple. The same is for Ancient Middle East.
An interesting comment.
So let me add to that (I have some background in high production agriculture)
As far as I know the Egyptians owned their own land. The King and the temples also owned a good deal of land which they used to support themselves, but I think that most of the land was owned outright by the peasants.
The irrigation channels and the very crude techniques used to get water out of the Nile and into the ditches didn’t look like government sponsored operations. Basically buckets on a wheel.
They also had surveyors, apparently a job description nearly as old as prostition.
Egypt did not have as many people as it does today. Chronic illness as well as extremely low ag yield by today’s standards (1/16th of today’s yield? Maybe lower..) kept the population tamped down. Since Egypt was in the water borne disease zone I suspect that dysentery and malaria were common and took a lot of Egyptians early in life.
(The death rate in Massachusetts from water borne diseases was 1/20th of the rate of the Cheasapeake Bay area in Colonial America. Massachusetts was above the latitude in which water borne disease was common. That was one of the reasons the Pilgrims landed that far North. The latitude at which water borne disease was an issue was well known to our ancestors. I had always thought that it was a bit odd that the pilgrims went to a cold snowy area on the continent, but now it makes a lot sense to me.)
I am also not sure that the irrigation operations were quite as extenisve as the yearly flooding provide a huge amount of ground water in soil that was capable of holding on to it. I used to walk our fields that were located on the Mississippi and the black dirt was amazing. A bit like walking on a mattress as the dirt compresses one half to a full inch as you walk on it.
The flooding would also decrease the the amount of free nitrogen in the soil by large amounts and would really knock back the possible yield.
I am going to look at this as it simply is question I am sure has been asked but I have never asked it myself. Thanks for the comment.