If you go back far enough, there were no cities at all. Nevertheless, I think there is a wonderful "city" concept in many old towns around the world, and especially in Europe. If you move to Silicon Valley, and you spend some significant fraction of your life there, then your day to day quality of life is seriously affected by this. This discussion thread may be getting "off topic", although it is about an article telling entrepreneurs from all around the world to come to Silicon Valley if they possibly can. I am warning them. It's not a paradise (in my opinion.)
There are two possible future outcomes I can think of.
1. We have an oil crisis, and cities return to the way they used to be, over the course of time.
2. Alternative energies gracefully take the place of oil, there is no crisis, and things continue as they have been.
Oddly, the crisis outcome is more appealing.