Yes, this is what they do, up to a point. Thanks to modern transportation (cars and good roads) and telecommunication (phones and internet) we've been able to

Yes, this is what they do, up to a point. Thanks to modern transportation (cars and good roads) and telecommunication (phones and internet) we've been able to expand our cities to levels that were unachievable during ancient times. But with current tech, there are still practical limits. The undeniable proof is the huge pressure on the housing market. If it was practical to simply build houses in the middle of nowhere, people would do that instead of fighting for small space in large cities.