[nine_zeros]

The path to building a city involves first building a small town with some kind of economic activity. Because of a lack of people (especially young people), it's hard to create a brand new city with a vibrant economy. Most of the existing young people in America move to existing big cities. Small cities are becoming bigger.

This is unlike China where cities were built en masse to house migrants from rural areas. America just doesn't have the same volume of workers.

America is still pretty empty.