I fled SF and I know a bunch of similar people. Startups are still founded there for the address, not the local talent pool. The address is there because of inertia, not because of inherent advantage. If I were to create a startup I wouldn't even consider doing it in SF now. It is a waste of money that could be put towards the idea. The US is clearly on an ant-intellectual path. People default to here because of inertia but every attack on immigrants, every high level decision based on quack science and personal gain and every attack on our institutions supporting the development of the next generation is putting inertia elsewhere. It is clear as day that the US is only keeping any kind of advantage right now due to inertia and threat and not innovation and effort.