Presumably Google still has a massive Bay Area presence because it's more profitable for them to stay there than move, at least that's what is implied. Maybe they should be pushing hard for the city to build more housing. But it seems like the current residents in that area are holding their hands to their ears, closing their eyes and shouting away any evidence that more people require more housing, or things will get worse. I can see your point that Google should probably move if that's the case, but the costs involved probably make it super unrealistic for that to happen, at least in the near future.
Where would you move Google, at this point, if you were in charge? There's not a single city -- in the US, at least -- that I can think of that would be prepared, with the right infrastructure or ready to build out a lot more. That probably factors into Google's decision making process as well.
Maybe we should be going back to the idea of company towns. Or possibly have urban planners building new cities from the ground up with proper infrastructure, housing, transportation, etc. that have the ability to expand for new residents and companies. Certainly the big cities in the US don't have that capability due to our car based infrastructure and our attraction to 30 year mortgages on suburban houses.