Well, what in your mind might be the reasons people of talent leave Europe to come to the US to start their tech empires
See Skype, Nokia, Shazam.
China’s doing it too. They bought ARM shortly after Brexit.
I don’t doubt that there is a migratory factor, though I don’t believe it’s primarily due to salary or other compensation as I assume you’re inferring- a cornucopia of tech giants is going to attract talent from the world over.
So a consequence of centralisation is more centralisation.