“Let's leave the cities for the promise
of peace and harmony.”
By spreading people out instead of concentrating people in cities, the world became connected. Every village is next to other villages, without any marginally inhabited land in between. People no longer have regional superior race kind of thinking. The world became one.
With equality there's no need for crime caused by greed or just to survive. Everything became simpler. Without having to worry about the future, people are able to use their time and energy for things that will benefit society not just make them money. By spreading out we ended all the social problems that come from living on top of each other, but most importantly, by spreading out we can live in a peaceful environment. As we know, we are products of our environment.
For some bizarre reason, years ago it became normal to consider people as somehow separate from nature. This kind of thinking may have come about when the powers that be were deciding who gets to go to heaven and who doesn't. Obviously animals and plants can't go to heaven so we must be different.
Spreading out brought people back to nature and brought spirituality back to include all life. Spreading out filled in the gaps enabling the natural flow of our genes and with half the land for nature, the genes of plants and animals too.
It is true that cities provided an environment for like minded people to come together to work on big scientific problems. It is true that the Internet can't replace face to face interaction. It was feared that without cities, great minds would be wasted without interaction with other great minds, but these fears were unfounded. Once we had gained equality and everyone got the chance to follow their dreams, all minds started to become great.