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.
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.
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.