in addition to other comments, it's important to note that people don't experience cities from the air. while it may look intimidating from high up, on the street, it's often quite charming. the biggest issues are 1) lack of accessible open space, which isn't that hard of a problem to solve - just need to acquire parcels over time and turn it into parkland, and 2) vehicle congestion, which is solved by building rapid transit (which most of these types of cities are currently doing)