Kip Robinson recently posted a thoughtful look at the impending death of Stack Overflow; I highly recommend it. The diagram he posted in his article is remarkable (I'm reproducing it below for convenience).

As the graph demonstrates, essentially no one posts questions or answers to Stack Overflow anymore. One reason for this, as Kip posits, is that AI agents don't punish you for asking bad questions. I think that's a really good insight: AI tools are welcoming environments (sometimes overly so), rather than discouraging environments like Stack Overflow was.

One other angle I can think of is that AI agents don't punish you for being too specific. In my past dealings with Stack Overflow, I've often been frustrated by having questions closed for not being generic enough. Spending time to boil my specific problem down to something generic in order to pass the necessary post qualifications was wasted effort. Adding to this frustration, receiving an answer occasionally took hours (or days).

With modern LLMs, the opposite is true in my experience: the more verbose and specific your question, the more likely you are to get a very helpful answer. In addition, the answer is virtually instantaneous!

Anecdotally, I haven't used Stack Overflow in years (either for questions or answers). With the advent of AI, I don't even visit it to read previously posted answers. I guess it was helpful in its day, but the world has apparently moved on. So have I.