Big cities are played out
The megacity/suburb sprawl as a way of populating the world is a 20th century idea that no longer applies in the 21st century. Small town living has it over urban living in every aspect you might consider.
Our town (pop. ~ 3600) is economically viable, unlike all the big cities and suburban areas, which are mostly bankrupt. There's much less crime because everyone knows everyone else's business. It's a cleaner environment with better schools and friendlier people. A small town has all the benefits of urban/suburban living without any of the detriments.
I think that all the factors that originally led to big urban environments developing have been mitigated by modern technology. The mega city has seen its day.
Now, if we could only get a handle on our population growth, we could set about to make the planet a much better place.
