My attention was caught by this thing Gwern said when he was interviewed by Dwarkesh Patel:
I have learned far more from editing Wikipedia than I learned from any of my school or college training. Everything I learned about writing I learned by editing Wikipedia.
It was a very natural progression from the relatively passive experience of rabbit-holing—where you just read everything you can about a topic—to compiling that and synthesizing it on Wikipedia. You go from piecemeal, a little bit here and there, to writing full articles. Once you are able to write good full Wikipedia articles and summarize all your work, now you can go off on your own and pursue entirely different kinds of writing now that you have learned to complete things and get them across the finish line.
It would be difficult to do that with the current English Wikipedia. It’s objectively just a much larger Wikipedia than it was back in like 2004. But not only are there far more articles filled in at this point, the editing community is also much more hostile to content contribution, particularly very detailed, obsessive, rabbit hole-y kind of research projects. They would just delete it or tell you that this is not for original research or that you’re not using approved sources.
You know how productive scientists were in the early 1900s? And people ask, ‘where is today’s John von Neumann’ or whatnot? It occurs to me the answer might be that there being a new field with lots of visible low hanging fruit trains people up a lot in intellectual agency (in addition to, obviously, providing the fruit to pluck).
It wasn’t good for civilization that Wikipedia was in a nascent less-helpful stage when Gwern was a kid, but it was good for Gwern.
“What unfilled niches does your civilization have? (where you can do something real to fill them in at age 20)” seems like a direct factor influencing how productive the outliers are going to be 10 years later. And interestingly, it’s approximately unhackable. You can’t create unfilled niches that 20 year olds can jump into. If you try to do it artificially, it’s Not Real.