Either build more concentrated housing like Manhattan or make commuting from a longer distance more efficient. Perhaps a little of both.
Google has $60 billion in overseas cash. Negotiate a tax deal to build the Google Maglev from SF to San Jose, turning the 50 mile journey into a 20 minute commute.
And to that point; you can sit in an office in another city or state which costs a fraction. You are not in silicon valley just because you need to sit together in your startup right?
I think more likely alternatives are:
* build up if a high density coalition can be assembled (unlikely, but possible)
Or
* people stop moving to the bay area or leave when they are ready to settle down. Remote work becoming more acceptable may be part of this.
We face some of the same issues where I am (Boulder), but of course nothing near the intensity. We have huge chunks of uninhabited plains to our east that are being built out. If we have the water for it, and can handle the in commute traffic, we are good to go. (I realize those are big ifs!)
Manhattan is not affordable either. Especially considering that getting kids in good schools is famously challenging.
I think higher-density zoning is an easier thing to do in real life, but if this were Sim City I'd concentrate on making more areas be somewhat independent, so we don't all feel the need to go to the same spot
But "Mag lev to Stockton" doesn't sound so sexy despite being a more rational idea.
Maybe Google instead ought to learn about remote work instead of blowing billions on a Mag Lev.