Startup stock options are not encouraged at a policy level in most of the EU countries.
https://www.notoptional.eu/en/country-ranking
No good stock options, not many getting rich after successful exits. Hence not many to fund the next good venture. A handful of VCs and some banks who had traditional money.
Most of the successful European companies look for an acquisition by a US company as an exit path. Silicon valley has an eco system of people who had successful exits funding the next startup. It is quite rare in Europe.