The number of academics who achieve a 50 year career is vanishingly small. I can think of a handful I met in a decade. To call the other 99.9% of academia in-training is a bit of a mis-nomer, whether it's the accepted terminology or not. That was my point.
And my point was that academics whose primary job is doing research in someone else's project are even rarer than tenured professors in research universities.
A postdoc is primarily a career advancement position rather than something where you are expected to contribute full time. Such positions are also pretty rare. There are something like 70k postdocs in the US, vs. almost 190k tenured or tenure-track full-time faculty in research universities.
