San Francisco is only 7 miles square and nearly a 1/3 is the Sunset and the Richmond which is almost entirely 2 story max, single family homes. Measure K which limited most of the big construction to South of Market pushed everything into an already packed downtown. Not everyone wants, or can afford, a condo on the 30th floor.

I also hadn't realized how much of the city is green space. Kind of amazing that has been preserved.