They were built really quickly, often on the outskirts of cities, where there was plenty of undeveloped land. They were often placed in large groups. The landscape was bleak at the beginning. Huge gray apartment blocks spaced in a random fashion.
There was a lot of space between them. Large empty spaces. Sure, footpaths were set down, grass was sown, and small trees were planted. But in the beginning, they looked bleak.
Fast forward thirty or forty years. The trees have grown huge. The playgrounds are no longer depressing. On the outside, they are actually very nice. They were insulated and painted and are no longer drab. These developments have a park vibe to the, with the large trees, asymmetric building placement, and large open spaces.
This is not taking into account the conditions inside, as those varied from country to country, city to city, and development to development. Many have been modernized, but some still have the fundamental problems mentioned by others.
The moral of the story is that large trees and open spaces make for pleasant living.