What you do find a lot of in tech hubs is the type of people who move to tech hubs. This often means that in a certain type of company you get better "culture fit" by using a geographic filter (thus avoiding illegally filtering by protected characteristics), and you definitely get a higher percentage of people who are willing to structure their life around their career. And when you get enough of those people in a room together, they're certainly the types that will happily persuade each other that they represent "the best talent in the world."

Software is a potent leveler—all you need is a computer and you're on equal footing with the rest of the world—and I find that the best programmers are the ones who learned to do it for fun and only later made a career out of it. Those people are equally distributed across much of the world at this point, and if anything there are fewer of them (as a percentage of job applicants) in the tech hubs because the tech hubs attract those who chose software for the money.