Nobody is willing to pay the price difference, that's why scaling up big tech in Europe natively doesn't happen. If someone were paying it, then we would have big tech natively in Europe, and we haven't.
Could you give an example of a technology that needs to be scaled up in Europe?
Competitors to Microsoft, Apple, Google, Facebook, Amazon/AWS, Netflix. The only thing we have that's even vaguely comparable that started in Europe is Spotify and it's 1/3 the size of Netflix, which itself is the smallest of the US tech giants.
You have listed many companies that do many different things so I don't really know what you mean. But in any case, how would a natively European competitor benefit Europe? Are we talking about money, jobs or what exactly?
Money, jobs, IP, skills, influence. As I pointed out in another thread, Europe loses a lot of top IT/CS graduates to the US every year because they can earn 3x to 5x the money.