There was this little thing called World Wars that decimated a lot of capital of all kinds (demographic, financial, materiel, infrastructure) which USA exited i

There was this little thing called World Wars that decimated a lot of capital of all kinds (demographic, financial, materiel, infrastructure) which USA exited in completely different position - one of oversupply of all the above to the point that Marshall Plan helped USA as much as it helped Europe by providing an extension of demand for USA industry. The entire Silicon Valley exists because that windfall was allowed for the most ridiculous defense spending in the world which went on to create the baseline that private investment could continue (though there was considerable dip when the defense spending got cut in 1990s, private demand by then could continue). In comparison, wider common market in EU is mostly, well, a thing from 1993 - the EEC had partial one, but it's only since 1993 that you could reasonably treat EU market similarly as USA one, which heavily impacted just how big you could grow as company (you need people to buy your products/services after all). And you still have to deal with things like multiple languages whereas for USA it's viable to have just limited english support. Combine this with huge impact of retirement funds looking for investment opportunities and zero interest rates for long time, you have conditions where in USA you could get multi million investment for a juice company with overengineered juicer. It's essentially law of large numbers there, lots of churn will get you more even if actual successful companies are lower percentage - the scale does it. And let's be honest, a lot of US investment capital (including Y-Combinator!) did a lot to ensure that prospective founders from Europe founded the company at least partially in USA (in case of YC, even focusing on SFBA). Also, you mention GDPR, when it's one of the easiest regulations to deal with in my experience (it actually cleared up stuff that existed before). The DSA and DMA only become really strict once you have MAU bigger than adult population of many of EU countries (more than 10% of total EU population). Honestly, for startup, a lot of it is easy checklist of "don't do that" - the most you might have to do is to look at what goes through the brains of your marketing dept once you have one and prevent them from going crazy with tag manager... something that your users would be happy about too. If anything is missing, it's the large VC industry that was incubated through decades of defense and government spending in USA (guaranteeing demand and customers).