While that is true, LA makes up a big portion of that "over 10%" hardly anyone in LA lives in anything remotely like high-density housing or lives there for much beyond the fantastic weather and job opportunities. Also, you don't do anything to address the parent comments point that plenty of people who live in higher-density areas would prefer to move to somewhere more rural, but can't because of life.

Hundreds of thousands of people live in high density areas of Los Angeles with densities far exceeding San Francisco's most dense areas. Also people live in LA for the same reason they live in other big cities, because it's incredibly diverse and vibrant. Traffic may be bad, but most people aren't in transit for that long anyways since the city is still pretty dense, and you can get everything you need within your neighborhood (where many neighborhoods are totally walkable).

but (hundreds of thousands[living in high density LA]) + (hundereds of thousands [living in high density SF]) + 8 million (living in NYC) =/= 10% * 350 million.

In fact, if we generously estimate that 10 million people live in high density metro areas that don't rely on cars we are looking at less than 3% of the US population. I think that is something to sneeze at.

100% of the my friends and family who live in New York would live nowhere else in the country in spite of the extreme costs of living in Manhattan, when they could have equal incomes elsewhere.

I know it's hard for you to believe, but some people like living in high density areas.

I understand that. But at the same time I know plenty of people who live in SF who would love to move to a more rural area, but they or their spouse can't find work in their field outside of metro areas and SF is close to their rural roots. Some people don't like living in high density areas, but find themselves their out of circumstance.

LA is almost entirely car-focused.

SF only has a population of one million.

Basically the US has NYC and parts of Chicago as emblems of urban density.

The US has over 200 zip codes with a population density of 20k/sqmile. While 20k/sqmile isn't an 'emblem of urban density' it does show there are several locations a person that enjoys high density can live in.

I know it’s because it’s HN, but SF is just not that big of a city to be included with the other two. Maybe include Houston, Philadelphia, or Phoenix. SF isn’t even in the top ten.

The San Jose-San Francisco-Oakland Combined Statistical Area is estimated at 8.8 million, putting it fifth, after Greater NYC, Greater LA, Greater Chicago, and the Washington DC metro area including Baltimore. [0]

[0] https://en.wikipedia.org/wiki/Combined_statistical_area