That's an element, but you can't discount organized gangs of bandits who ran the early protection rackets on the first farmers.
Well, that's pretty much what I was talking about. The difference was that you couldn't escape the protection rackets in the river valleys. You're in the Nile Valley. Somebody grabs control of the irrigation system and says you gotta pay up or else. What do you do? Walk off into the desert?
The first agriculture seems to have been in Turkey but the state didn't appear until thousands of years later. It has to intensify before they can catch you in their racket. Otherwise you just walk away from the jerkfaces and set up a new farm elsewhere.