In the decades following World War II, many governments invested in civic infrastructure to keep their economies growing and wipe away the bombed neighbourhoods, which were visible vestiges of war. Infrastructure also included massive urban renewal schemes which replaced whole neighbourhoods in the central cores of cities. Greece stands out as an exception. It might explain why the cities there look and feel so different.
Housing was definitely needed. People were flocking to the cities from the countryside. Local builders teamed with landowners to replace existing single dwellings with a short stack of flats. The owner occupied one and rented out the others. This created mixed income neighbourhoods when replicated on a large scale.
As for mixed land uses in Greece, anyone operating a business in a residential area can do so openly. The land use laws permit business activities, except for heavy industry. Many stacks of flats have commercial activities at ground level.
Read more the strengths and limits of Greece’s post-war housing solution in Bloomberg CityLab: Behind the Accidentally Resilient Design of Athens Apartments