It's not. I'd recommend Jane Jacobs' "The Death and Life of Great American Cities" to anyone interested in a comprehensive picture of what it takes to make cities livable: https://www.amazon.com/Death-Life-Great-American-Cities/dp/0...

Also read up on all the work Singapore is doing to increase density without ruining their economy or environment while improving livability.

And some further reading on the dynamics of city growth: http://journals.plos.org/plosone/article?id=10.1371/journal....

I love thinking about this stuff, complex and fascinating :)