... but it still doesn't predict actual success in my experience. I was "gifted program" adjacent growing up (all my friends were in these programs in the late 70s -> 80s) -- all earned high grades and test scores -- but many are now puzzled why they are not showered with $$ and success into present day. Well, they don't think they are successful to where they should be.
Well yeah, our society doesn't really reward hard work and advanced knowledge for the many. There are the rare exceptions, but for the most part to make $$$ you need to buy into the current system which is all about making spreadsheet numbers go up YoY at the cost of everything else. If you don't do that, well I hope you can find a niche somewhere that is stable and comfortable.