Tokyo and Mexico City have very, very few buildings over five stories and still have double the density of SF. Paris and Barcelona have almost none over seven stories and have four times the density of SF.

So it doesn't have to be high rises and skyscrapers. SF can look like SF and build enough to make living affordable.

Of course, the real problem is the peninsula cities that insist on densities much lower than one third of SF. 80% of buildable land on the peninsula is tied up there being wasted.