There is no shortage of land, there is a shortage of efficient transportation. All this talk of building up and creative ideas around housing is great but the ultimate problem is transportation. To solve the problem of housing in LA, a person should be able to live in Reno,Nevada and work somewhere in Santa Monica, CA. I'm not saying I have a solution, I'm just pointing out the problem domain.
The US does not have modern transportation infrastructure like similarly sized countries like China. Generally speaking, housing is built near bodies of water or alongside transportation towards bodies of water. Even issues like NIMBYism can be resolved by constructing underground bullet trains that won't affect appearances. This is a hard problem, but not an unsolvable problem. It isn't just economies of scale, government investment, clever economic strategies,etc.. that are needed but actual revolutions in construction technology and transportation. Timelines for construction that are only few years not decades. But alas, I fear the politics of these days would not allow for this.
The US does not have modern transportation infrastructure like similarly sized countries like China. Generally speaking, housing is built near bodies of water or alongside transportation towards bodies of water. Even issues like NIMBYism can be resolved by constructing underground bullet trains that won't affect appearances. This is a hard problem, but not an unsolvable problem. It isn't just economies of scale, government investment, clever economic strategies,etc.. that are needed but actual revolutions in construction technology and transportation. Timelines for construction that are only few years not decades. But alas, I fear the politics of these days would not allow for this.