I’ve been mentoring startups in EU for over 10 years and there were only a handful that had issues with regulation, but 95% had issues with a language/country lock in.
It's not striking that the EU is as wealthy per-person as it is and has so few tech unicorns. It's also not striking for a region with hundreds of millions of people. What's striking is that despite being wealthy and populous, the region hasn't done too well with tech.
I'd say that it's even changed during my own lifetime. There was a time when German cars had a much larger market share and Nokia was a dominant phone company. Nokia failed the transition into the smartphone era and while German cars are still great, their market share in EVs is much, much smaller. And it's not like there's a lack of talent. Plenty of Europeans are building huge tech companies, but a large fraction are choosing to do so in the US or other similar markets, like Canada (e.g., Shopify).
I'd attribute most of the gap to regulatory and cultural difference.