It's also exceptionally difficult and time consuming to rapidly scale through the EU with its many local economies/languages/cultures, versus the giant and quasi homogenous US market. And you get Canada pretty much as a freebie with the US market. That's $24.x trillion in economy in just two markets (nearly 50% larger than the EU). By the time you slog your way through a bunch of the EU markets, you'll find that a US venture capital funded competitor is already several times larger and turning its attention to your home market/s (putting you on the defensive, while they've locked up the lucrative US market and can pummel you endlessly with the financial resevoir that comes with that).
If you're in a smaller nation in the EU, the ideal is to go right after the US market first as a springboard (assuming the product/service is globally useful and will benefit from grabbing the US market). That's especially true if you're early and have an opportunity to lead the US market.
It must be said that large scale, extreme/first-of-a-kind tests are simply not possible over here: not in the energy sector, not with autonomous AI deployment, not using any sort of active biochemicals/pharma, not as hostile moves in the fintech or the information sectors. This simply makes innovation much slower and pretty bureaucratic, but we cannot say there is no innovation at all, it generally being funded in the end under one of the numerous EU grants.
Most of Europe's engineers work in large corporations that were created ages ago, and subsisted on government procurement of infrastructure, defence, or as subcontractors/staffing agencies to industry. And government spending in Europe has also been much tighter than USA.
Most "new" media/tech companies are founded as "spin-offs" from older media companies/publishers/telcos/banks. The engineering in Europe's early web efforts was considered as important as copy-machine technicians. This is changing, but the attitude is still deeply ingrained: people are either decision makers or "technicians".
Of course not, it is just mind numbing regulation coupled with systematic risk aversion. Many SV startups would never have gained traction starting over from Europe, neither financially nor for large-scale deployment authorisation.