I’m currently building something in a much more lax area, but even here, the few parts that require permits/inspection are by far the largest hurdles, because they impose a rigid sequential order of operations that have to happen before I can move on, and require a licensed master tradesman to pull the permit, whereas most other things can generally proceed as materials/equipment/people become available.
On your point about local government getting greedy, I went to the state of the county address in our area recently, and the county executive gave a long laundry list of how many millions he was splashing out to x and y, to fanfare for each spending figure, as if the goal was to spend more, rather than get the maximal impact for the dollars. I guess most of the audience were people from those departments receiving the additional money, but as a non-government worker, it was a bit sickening.
I don't see how a contractor could be efficient at all with this setup - I'm assuming they're better at getting things through building and planning, but even if it only took them a couple weeks, they'd need a pretty big pipeline to keep busy, to compensate for all the stalls.
zoning regulations and entitlements are only one piece of the puzzle. a significant piece, for sure.
Government permitting is now a huge percentage of the cost of building a house in many US metros. CA is maybe the worst offender.
It's not just NIMBY. State and local governments have gotten exceedingly greedy over the past several years.