California is the most regulated US state which is where most of the companies you mention started. A much more likely and logical reason is what the other repl

California is the most regulated US state which is where most of the companies you mention started. A much more likely and logical reason is what the other reply to your post states, the EU is a very fragmented market. There are also cultural differences certainly at play. But this very American trope that regulations are bad for business is misguided, it is fact the strong rule of law in the US and regulations that offer a great framework for startups in addition to the largest single market in the world, and the government funding a lot of research and dev through defense spending.