1. The US has almost 330 million people; Europe has 740 million - but we're spread over so many different countries / policies / cultures etc. Hell, eastern Europe was locked out up until 30 years ago, and didn't stat to see industrial prosperity until 20 years ago.
2. USA had a massive advantage after WW2, while Europe was still in shambles. The rebuilding of Europe wasn't really completed until the 50s and 60s, at a time when the US experienced its golden age of industrial development.
3. More rich people and more investors compared to Europe, from earlier on, coupled with excellent schools that could produce and feed talent into the industry.
Sure, we here in Europe have had excellent schools, but nowhere near the financial backings. In many countries, financial backing of tech and companies have been a gov / state affair, which in turn can be extremely limited compared to private investors.
etc.