Cities in the US are more expensive due to housing policy, as you mention, but also because cities as the engine of American business and growth are subsidizing the rest of the nation. A significant chunk of every city dweller's money ends up in taxes that are transferred to far less efficient and less wealthy non city areas.

Take away the wealth transfer from cities to non urban areas and the only people living in rural areas will be the wealthiest and end of the world preppers.