10 billion a year in global tax avoidance for those tech companies combined doesn't sound like a lot considering their revenue is around 600 billion a year.
Also consider that all the workers are also tax payers and they want the company to continue existing, their taxes would also go towards protecting the bay. Their tax dollars wouldn't exist in California if those tech companies weren't there.
It is across the entire world, it wouldn't be used in the bay area. They already pay taxes properly for all the workers and buildings they have in the bay area, if that isn't enough then they ought to raise those taxes since they should cover the cost of operating there.
The discussion is about issues in the bay area. They contribute a huge amount to the tax base there, so saying they don't pay taxes isn't fruitful to this discussion. If those taxes isn't enough to handle issues in the bay area then bay area taxes should be increased, simple as that. And if that makes tech companies leave the area then those tech companies couldn't afford to operate there, and if they can't afford it then nobody can and everyone would have to leave the area.
Edit: The main point is that nobody can say that San Francisco has less money with those tech companies operating there than they would if those tech companies left. They are among the richest places on earth and should easily be afford any measures that can be afforded anywhere.
