Generative AI can also increase the amount of good content, too. If I knew that a particular human vouched for an AI-generated code snippet, I would trust it as much as a hand-written StackOverflow answer. You can bring the entire arsenal of community and reputation-building to have more people vouching for answers and double-checking others.
That's why the future of StackOverflow is more like Phind, the code-specific LLM that looks like a search engine. StackOverflow already has the community. Now, they need to keep people there to check AI-generated answers.
And there's second order benefits, too. You could have AI check old answers, even human ones, on a regular basis. Imagine if an answer is marked "obsolete" because the AI found a more modern solution, or if it found a security issue.