On the European side, it was one of the greatest acts of self-sabotage seen at a civilizational scale. At the American end, it was a boon. There were more Noble prize winners hanging around coffee machines than you could shake a stick at.
The analysis fails to account for this; for e.g. they weren't intelligent just because they were of jewish heritage. They fled because they were intelligent and jewish. And those who didn't flee were killed. Is it any wonder that a list of fleeing European geniuses that the US govt. allowed entry into the States is dominated by jewish geniuses?
Out of this list, the only anomaly that truly stands out, and is perhaps the reason why the term "The Martians" was coined is John von Neumann. Quoting from a prior comment,
On a more shameless note, I'm compiling this as a part of my Project Karl. It's one of those books that I think everyone should know about and read, but few do. https://www.projectkarl.com