It's a long standing and complex trend.

It's worth remembering that Silicon Valley got started way back in the 50s with Shockley's transistors. Then Microsoft in the 80s and Amazon, Google in the 1990s.

What was going on in Europe during these times?

For most of the 20th century continental Europe was a hotbed of dictators and extremists. The first half was dominated by two world wars that flattened everything. The second half saw dictatorships across all of eastern Europe that kept it impoverished, there were dictatorships in Spain and Greece and significant political instability and corruption for decades in Italy.

Britain, which came out of WW2 the strongest having been on the winning side, was nonetheless totally wrecked and worse still, the population concluded that the government must be pretty good at things due both to the victory and years of news suppression which prevented people learning about government errors (e.g. Exercise Tiger). So Britain became strongly socialist and remained that way until Thatcher in the 80s. The economic destruction this socialist environment wrecked was extreme enough that the UK had to go to the IMF for a bailout and was suffering things like electricity shortages during the worst periods of the 1970s. It was a place where even established businesses struggled to survive, so the idea of a startup culture or creating advanced tech firms was totally absurd - the government had given up even attempting to fix things and unions under the control of Marxists were practically shadow governments in and of themselves.

In other words, if you look at the time that the USA was establishing startups like Intel that'd become huge tech firms, which then spawned generations of technically skilled VCs, Europe was mostly either actual communist dictatorships or so hard left that the idea of creating dynamic new businesses was a pipe dream. There was no environment in which to create the generations of successful entrepreneurs that America benefits from.

Interestingly, Germany did much better than Britain during this time because - having had their faith in government wisdom destroyed by the Nazis - Germany deregulated and experienced much better economic growth, despite having been cleaved in half by the Soviets. This sowed the seeds of German economic strength dominating the Euro today.

Things only really changed for most of Europe in the 1990s with the fall of the USSR, reunification of Germany and Thatcher's reforms having turned around the UK. But then Europe collectively decided that the right path into the future was to slowly merge together under a vast centralised bureaucracy centred in Brussels, one which had its roots in the Ventotene Manifesto, a document written by communists in the 40s. Remarkably, the EU to this day still has never really shaken a vague sense that communism was roughly in the right area. Its ultra-powerful unaccountable Commission President (Juncker) routinely makes statements like "when it gets serious, you have to lie" and he travelled to the birthplace of Karl Marx where he defended Marx's legacy:

https://www.independent.co.uk/news/uk/politics/karl-marx-jea...

The EU has historically often had former communists in its most senior positions and does things in ways that are reminiscent of the USSR (e.g. a Parliament that can't actually overrule the unelected parts of the government). No surprise that it takes an ambivalent view of business, especially successful American business, and largely defines itself as a defender of The People against Capital.

Combined with no culture of granting equity and we have today's situation.