It seems to me much more about group incentives than some nefarious lockstep plan. Existing homeowners incentives are liking things as they are and increasing wealth on paper. What’s more interesting is what changed since the ~60s inflection, since before, things were built. People literally experienced NYC grow into a megalopolis. I’d say it’s more likely that more democracy was the problem in stifling things, when every environmental review and city council meeting blocked things and threw out city mayors that were pro building. China is totalitarian and they are the ones who manage to rapidly build cities and bullet trains out of nothing.