There's no need for the city to build it, they have zoning plans, and they can easily zone "that corn field over here" into an aera of commie-style apartment buildings (5+ floors, commercial on ground floors, apartments above, garages underground), and assign some percentage of space for green areas.

I live in one of those used-to-be-commie countries, and we somehow manage to keep cornfields in prime locations, and in many areas, the most the local government allows you to build is a two-apartment two-story house, but none of the non-built land is actually buildable, so you need to demolish something else first. Here and there someone is able to build something with maybe 6-8 apartments (probably with an envelope switching hands), but that's it.

It's as if some rich people connected to the government managed to get a lot of realestate in the 1990s when communism fell, and now they don't want prices to drop. But hey, we're building office buildings without any issues and making airbnb even easier instead... so yeah... the situation is pretty bad.