But SO was never a place to just talk to others. It's not a general purpose discussion site. It could have been a friendly place, but users still would have left, because it's just far easier to get an immediate answer from AI, and those answers have only been getting better.

Yeah, the place could be very hostile, but that hostility didn't crater questions before ChatGPT was released.

In the early years it very much was. You could ask just about anything that was programming related and had a question mark. In the middle times of SO a lot of those became "locked for historical preservation" and new ones weren't allowed.