Agreed, I found SO and Quora and similar sites with general or specific question/answer based communities weak long before AI.

AI replaced Google Search in many ways more directly on arrival than those.

SO to me was weak as it had outdated answers to outdated questions (yet related to search queries) that nobody maintained well.. and the community more focused on patronising to push their point of view than being essentially objective in many ways.

that was a total killer to me and I started preferring to come back to books, manuals and researching topics myself than short cuts like SO.. and that research is heavily optimised during AI/LLM era, yes, but that's just one of many nails to SO's coffin.