With different policy, there could be more housing built on the same land. The most scarce land there is shouldn’t be predominantly zoned for only low density single family homes.
The uber wealthy have their gated communities in the hills.
The very wealthy have their lock on places like Carmel.
The upper-middle class in Santa Cruz or Half Moon Bay try to prevent new condos (or student housing) from being built, because it "destroys the community character."
Everyone wants to pull the ladder up behind them.
Austin has been begrudgingly growing up, not without a raft of complaints from locals, because the property taxes are high enough to make selling to a developer tempting. In return, Austin has remained relatively affordable in comparison to other tech hubs.