SO, at its best, is numerous highly-experienced and intelligent humans trying to demonstrate how clever they are. A bit like HN, you learn from watching the back and forth. I don't think this is something that LLMs can ever replicate. They don't have the egos and they certainly don't have the experience.
Whatever people's gripes about the site, I learned a hell of a lot from it. I still find solutions there, and think a world without it would be worse.