It isn’t just the houses, the schools, the sewers, the highways, or the public transit also need upgrades. Even then, a city like Seattle has been building a lot more than SF in the past decade, yet still keeps approaching it in property famous (and yes, we mean land value, not just the structures on them). I live in Ballard. And tons of low density SFHs are being torn down for three story luxury townhomes, and then there are the 5-6 story apartment blocks being built. And this isn’t uncommon in the region. I guess as we approach NYC density, we will approach its property prices as well?

These are very congested cities that need multiple new mass transit lines and freeways (at least) to accommodate the influx of new residents that would come with a massive housing boom. I'm not defending zoning laws or NYMBYism. If anything, many of the same laws restricting new housing are also restricting the ability to build new infrastructure quickly and affordably.