Stack Overflow could be the greatest website in the world; ChatGPT would still kill it. The experience is that much better. The universe is not fair.
In ChatGPT i actually ask questions, get answer, and use its response to either refine my questions or look up documentation.
Since I know that ChatGPT can't really code, I use its responses as a hint. I leaned a lot when using it to explore the capabilities of languages and libraries I'm not that familiar with.
On SO, the opposite happens. I seldom ask questions, since the site has a reputation of being hostile. I look for previous answers and just try whatever answer I found on my code. If it doesn't work, I try looking for another answer, rinse and repeat.
I follow some SO tags where I have domain expertise (there's an RSS feed for each tag, so that's convenient). Often I remember having seen that answered before, so I copy the entire headline and paste it into google, and see a good answer somewhere on the first result page. My domain expertise enables me to pick it out from the other results quickly; the asker would probably need minutes, quite likely tens of minutes. What to do? I personally vote to close as duplicate, which is friendly to you and hostile to the people who asked without searching. What would ChatGPT do, though?
Based on a single experiment, it'll rephrase the top answer in a confident, friendly, patient, informative manner. But the top answer was wrong for that question, for reasons that require domain expertise to understand (a five-word phrase whose meaning isn't a minor variant of its three-word prefix), and ChatGPT's answer nebulised that difference.
I find ChatGTP to be very good at some things. I worry for sites like SO, though. SO's genius is to find a way to make answering worthwhile for people like me, not just for the people who'd like to ask questions and get free answer from someone with domain expertise. Replicating that two-sided model with an AI in the middle seems very, very difficult.
And for someone who asks and is curious about things, this is a godsend. I am using it as a learning tool, and some of its answers contained information that would take a long time for me to find myself, and it triggered me to look for actual tutorials and documentation that actually improved me as a developer.
You argue that SO makes answering worthwhile, but ChatGPT actually makes asking worthwhile.
And as a sidenote, I have expertise in a bunch of things, but I don't answer questions on SO, as I'm not interested in dealing with people interested in competing on it for internet points. I write tutorials on places like Medium or Hackernoon instead.
But it would be foolish to deny that this is a demographic that exists, with a lot of drama attached to it (e.g.: https://meta.stackexchange.com/questions/331513/lets-take-a-...)
Just the mention of "staff" and "power users" gives me the feeling that this is a place to avoid. I go there to fetch existing answers, and of none are found, I just go elsewhere.