Image: Ouarzazate, Morocco. One thing that should be emphasized more in the official lore is that City-States harbor people who never leave the safety of city walls...

...and why should they? Desert means death, after all.

As such, the cities of Athas are supposed to be old, very old, densely packed with inhabited buildings, but also filled with abandoned ruins, where nobody wants to live because the local conditions make whole block (or even district) no longer interesting from the perspective of citizens.