This "assumption" is called Manhattan, where in fact 1.6 million people live in apartments, no more than a few blocks from a train that comes every few minutes.

This "assumption" is called Manhattan, where in fact 1.6 million people live in apartments, no more than a few blocks from a train that comes every few minutes. The economic conditions to reproduce this model are in several other places. The only reason it's not happening is our decision to ban it.