On the one hand, studies have suggested that nearly half of highly successful entrepreneurs/founders in the US are immigrants or children of immigrants. As the US becomes more authoritarian and more corrupt, its easy to imagine people choosing to do their new startup from, say, Berlin.
On the other hand, lots of people choose Singapore, too; rule-of-law-based country with relatively easy access to capital and relatively low taxes — but without actual democracy.
I'm aware of my own inherent bias of wanting democracy to be important to people when making this kind of calculation, but I'm not sure that we have any real evidence of that.
I do agree on Singapore, though. It's an interesting case in that the benevolent dictatorship offers most of the advantages of Western democracies in terms of a law-based contract between rulers and the ruled, but with (arguably) a more solid promise of long-term social stability. There's definitely a chance that we all end up in that situation.
A big part of it is obviously the relative effects of twentieth century wars, both hot and cold. However, we also need to be aware that in recent decades, the US has just offered a better deal for entrepreneurs than Europe. By that I mean it has been a democratic, rule-of-law-based country with relatively easy access to capital and relatively low taxes.
It still has the last two things, of course. But the first two are also essential, long-term, and if they're eroded then the US might stop looking like a better deal.