That just makes it sadder. European talent and knowledge, monetized by the US. Unfortunately the European economic order is incompatible with this kind of startup. We do not have the capital to fund it, because we do not have public markets as developed.
No, it's the research founding team mostly. The most important was the business team: Sam Altman, Reid Hoffman, Jessica Livingston, Elon Musk, Peter Thiel and Microsoft with their Azure supercomputers.
Edit: the only supercomputer industry in Europe was developed by France's first* president Charles De Gaulle (plan Calcul) for their country military or civil nuclear strategy which the US deep state did not like very much.
A French president unilaterally killed this plan Calcul under US advice and sold Bull to American company (Honeywell) despite the opportunity to merge Bull with a few European computer giants.