Stack Overflow is documentation, not Q&A, and that’s bad
The old Perl usenet newsgroup at comp.lang.perl.misc was partially for discussion, but was also for answers, and it was extremely hostile to beginners. It had a large FAQ, and the regulars regularly yelled at anyone who asked a question that was already answered. Understandable, because no one likes repeating themselves. But beginners are the ones least able to grok that whole thing, and beginners are the most likely to need help. The newsgroup set themselves up to be not helpful to the people who most needed help.
(Incidentally, the php.net site was great for help. There was a flat discussion under each function, sorted simply by most-recent-first, and goddamn if that didn’t answer most of my questions.)
Then Stack Overflow came, and everyone moved there. The unhelpful “read the FAQ. plonk” comments disappeared under downvotes, and helpful comments were upvoted.
At some point that “helpful” vibe changed. Stack Overflow ceased being a question and answer site, and begun calcifying into a documentation site. Questions are answered with “see this other answer”. There’s less rudeness than on usenet, but it’s approaching the same unhelpfullness.
Maybe it’s the fate of all Q&A sites to eventually become documentation sites. If you answer the question “correctly” once, why bother repeating yourself?
But I think repetition of answers is healthy. It lets the next generation of programmers practice their ability to write clearly and answer questions. It lets them collect their upvotes and badges. It’s good to have a healthy funnel where beginners learn how to ask questions, veterans learn how to write answers, and super-veterans learn how to moderate.