You’re comparing apples (the Big Apple, it turns out) and oranges. SF is 7 miles by 7 miles of hilly, earthquake prone land, surrounded on 3 sides by water. There is literally no “new land” available to build on, and redeveloping existing lots to rezone, or increase density, or whatever is costly and slow (and that’s true in most US cities, not just SF).

These are _essential_ complexities of land use in SF that are fairly unique to it, and hence comparisons to other cities are rarely useful.