But when you look at the land area of cities all over the world, what you see is that the vast majority of the land area of nearly every city in the world is given over to low density structures.
The biggest problem we face in the US is the logistics of how our system of land ownership intersects with and destroys the ability of communities to intentionally plan for density while mantaining human dignity.
A centralized planning system or "socialism" is not necessarily the right response.