Early Stack Overflow as an amazing "rubber duck" (see "rubber duck debugging").

Unfortunately in recent years it became such a traumatizing experience to post a question there (even if you made a perfectly legit question you'd likely get downvoted and closed ... and god help you if you posted a question with an issue).

It completely changed from "I posted a question I can answer myself, and someone said so in the comments" to "I posted ANY question and everyone on the site teamed up to get rid of that question".