Problem is that EU is not comparable in any manner to the US. For one, where do you suggest the Silicon Valley of EU is? London would've been a decent bet except that they just bailed.
As someone else mentioned, capital is way harder to raise (meaning slower to market) - and then an underrated factor which is equally important is how easy or difficult is it to sell as a nascent startup. At least in my industry (cybersecurity) it has been very hard in the EU vs US in the earlier stages of product maturity.
Much like the parent comment, I don't see this changing anytime soon and I'm fully betting on the fact US will keep their dominance in tech.
