Personally, I come from a country with so much money and so much opportunity that the only place that offers more of it is California. I would never have gotten off my arse to leave my nice life in Singapore unless I felt something about it was worth it.
Some days, I think about how someone like me or my friends who do similar jobs in Bangalore would move to SF far more easily than someone from a smaller city in the U.S. (in spite of the visas and challenges of international immigration, the proximity to that type of work is shorter because of networks). We’ve done a lot of this work in often many other places. It doesn’t mean we are better.
It means that global tech hubs have far more in common with each other than other American cities.