There are many people who never make it because they grow up under the wrong regime or in a place where no one will publish or publicise them.
For what it's worth, a lot of people think the Nazis undermined their own war machine by persecuting Jewish scientists.
Its still the case today, its just that America has gotten louder about its academic accomplishments being a key factor in economic success.
Your average German/Austrian universities have plenty of ex-pat Americans, there for precisely the fact that the education systems have such variety between the two nations. They are understated and under-represented in mainstream culture about academia, but for sure there are still Americans making the pilgrimage to older universities, for the diversity and strengths they offer.
America buys a lot of people in for its universities today, although of course there are bright Americans. German universities today are stricter and more rigorous in general than American ones.
I think the USA, like the UK, does tend to use name recognition. Oxford and Cambridge use interviews to filter out people, but are disproportionately represented in power structures.
Nevertheless, when it comes to top research, Germany has become a shadow of its former self. No way around it. This graph speaks volumes.
Prior to Nazism, Germans would collect as many science Nobel Prizes as the British, the French and the Americans together.
https://preview.redd.it/nobel-prizes-by-country-manually-upd...
While I agree with you that Germany doesn't have the intellectual prowess it once may have had, I don't think you can consider the Nobel prize a valid metric, personally. The Nobel prize has subverted itself many times over.
While German academia was rebuilding itself, American academia was chasing clout - one side effect being that the Nobel prize is more of a carnival attraction than an academic accomplishment.
They absolutely did, and German science never recovered its former dominant position after Hitler.
People don't even realize that as late as 100 years ago, Americans would travel to Germany for first-class university education. Harvard was good for networking and decent for overall education, but top notch science was done in places like Heidelberg.