Money is cheap in the US, and most of EU countries are quite pleasant to live without obscene amounts of money in the bank (basically thanks to public services), so any good offer it's quite convincing.
Not to mention that EU governments don't see tech companies as strategic assets, unlike the US/China.
So I guess it's a mix of culture/policies.
In the case of growth companies, it's definitely not a talent thing, the American financial system has a well developed pipeline for growing ideas and providing endless access to capital. Europe simply doesn't have that. We don't even have consolidated pricing for our stock markets, even after many decades under the EU, something the US has had since 1976. It's a joke, and no surprise all eyes are on and money flows into the US for speculative investment
This doesn't just apply to growth companies, or tech. It's a fundamental difference for all companies no matter how you segment Europe.
It is a difference that I don't think Europe will ever get past because changing it will be viewed as an attack on beliefs and ideals which can't trade-off to be similar to those in the US or China.
(FWIW: I'm an UK/Irish citizen living in the US.)
Maybe that was once true, but it certainly isn't true today.
Like, the whole TikTok thing is being ridiculous, in my point of view.
For example, strategic assets for the EU are airlines, or automotive industry, it's where you've seen government intervention.
But I'm not saying it's a good thing! In my country China bought the only Energy company we had - how isn't this considered a strategic asset?
Sometimes I think EU is too naive, or the whole "trying to lead by example" doesn't work financially/growth wise.
Only China has taken active steps in fostering those companies from nothing.
I don't know about western europe, but most of the tech startups in eastern europe have a sales/VC representation in the US for a reason.