Is there really an epidemic of troll answers? Not sure I've ever seen intentionally bad programming advice on reddit. (Unintentionally bad, sure.) Even 4chan of all places is rare in this regard, honestly, and in the cases where it does happen the answer is usually dripping with blatant sarcasm.
I'd guess totally made-up answers will be way, way, way more common with LLMs compared to any human social network.
There absolutely is an epidemic of troll answers on Reddit but not on programming subs, presumably precisely because of the aforementioned reasons. The kind of person that knows the actual answer (or has sufficient background knowledge to BS a believable answer) is the kind of person that won't post a troll answer in a programming sub. The kind of person that will post a troll answer won't have the requisite background knowledge and will be immediately "outed" and downvoted on the more legitimate (not r/all) subs, and eventually be discouraged from trying.
I'd guess totally made-up answers will be way, way, way more common with LLMs compared to any human social network.