Notably, Linux had a whole lot of howtos and faqs—not sure about authoritative sources but I guess The Linux Documentation Project is/was the largest. That was how people learned to do stuff without tearing their hair out, in the early–mid-2000s. I probably still have some of them lying around thanks to stockpiling like the apocalypse is nigh.

Of course, sparse or arcane documentation also leads to proliferation of educating books, by people ready to help for a reasonable sum. The existence of which market should say something about the truthfulness of ‘manpages are enough.’