As someone who did live and work in Silicon Valley my personal opinion is that the place is way overrated.
Sure there is a concentration of developers but most of them are of average skills. The place favors ‘specialists’ - which can fit in a small or a big team.
My advise to people who worship the place - come and work for few years in the Valley.
And then take the spirit of the place - ambition, drive, innovation, and leave for any other place.
I believe it is enough to have this spirit, anywhere in the world, to build something great.