SF is not the only place where housing is expensive. There are plenty of cities where they could build more housing and they don't because it isn't profitable or because they don't have the workers to build more, not because the government is telling them they can't.

It is expensive in those other places for similar reasons as SF -- the government either tells them they can't (through zoning), or makes it very expensive (through regulation, like IZ / "affordable" housing), or limit profitability (rent control), or some combination of the above. All of these reduce the supply of new housing.

Generally the cities where housing is expensive are exactly the ones where the government is telling people they can't build (or making it very expensive to get approval). Do you have a specific example of a city such as you claim?

Which cities, for example?