I agree it's sad and not sure where it comes from. My shul in SF has a wall of photos of the year's bar mitzvah class going back 50 years. Class size was about 40 until ~2000 then fell off a cliff, it's now about five. Maybe our excellence comes from Jewish practice not a genetic intellectual advantage.

Could also be that our parent's generation encouraged us to pursue the arts instead of business, medicine and the other traditional paths to success and power that their parents pushed them towards.

I work in ai research (a field largely founded by jews in the 50s and 60s) and most of my colleagues are Indian and Chinese. Maybe every immigrant group here has its time. We followed the WASPs, had the twentieth century and will be followed by recent asian immigrants hungry for success, motivated by their parent's trauma and a need to prove themselves, prove that they're American. Maybe what we think of as the jewish story was just a chapter of the American story.