There are different possibilities for doing research. Note how the current top comment here talks of becoming a "professor", and the featured article talks abou

There are different possibilities for doing research. Note how the current top comment here talks of becoming a "professor", and the featured article talks about "permanent staff position[s] at a university". If what you want is to do research, then what you want is not necessarily one of these. There are lots of research labs, both public and private, where you can get a permanent position. If you're in animal behavior, you might end up in a zoo, doing research part time or full time. These positions are overlooked by these articles since there you are not a "professor" at a "university". In other words, "X% of PhDs become professors" is a very misleading statistic. But yeah, that is still not enough to employ all the PhDs out there. I think in theoretical physics or math you just end up going into finance...