And Hollywood was nothing more than orange groves outside of Los Angeles before Lumiere invented the motion picture camera. Was that a one-off? So far that does seem to be the case. Lots of places will compete for the title of being the second-best version of "the center of the universe" for industry X, Y, or Z but there are very few examples of the center actually moving once it has established itself.
London wasn't always Europe's financial capital.
I believe that both Federal Radio (1909) and Hewlett Packard (1939) benefited from talented entrepreneurial engineers, risk capital, academic expertise, and a deep understanding of how to foster innovation not just manage invention.
Silicon Valley had none of that before Shockley and the Fairchildren (AKA tha Traitorous 8) rolled into town back in '57. Was that truly a one-off? The world's a big place.