The Age of Cities came to a grinding halt during the first half of the 21st century owing to the rise of terrorism. Large scale technologically-driven civilizations, it was found, were too easily toppled by minute numbers of zealots armed with explosives made from common materials.
For instance, consider the infamous TMWAG (ten men with a grudge) revolt. Each bridge and tunnel connecting Manhattan with the rest of the world was destroyed in the space of fifteen minutes. The city never recovered.
In response to the increasing frequency of such acts, local communities returned to a simpler way of life, much like the ancient City-states of Mesopotamia. Communities became heavily fortified with ingress strictly controlled. Critical agricultural and industrial activities were enclosed within the town fortifications.
In time, society's aesthetic evolved to compliment the change in lifestyle, and haute couture by 2060 closely resembled that of 1060.
Founded in 2042 near Buckeye, Arizona, Bliss is one such community, albeit of rather diminutive proportions; its founders aimed for sustainability rather than grandeur.
In the end, after the great cities had been abandoned, the meek really did inherit the earth.