Doesn't feel like the AI is the main driver. Many things changed over time - dev tools got better, editors got smarter, compilers got better error messages, various primary resources improved, tutorial websites, courses and youtube boomed. Another point of course is that each new question is more and more likely to be already answered. At some point the site pretty much covers most of what is to be answered.
> each new question is more and more likely to be already answered Yeah, except for when there should be current answers. Most of computing is in constant flux. There's a mountain of 10+ year old answers that simply don't apply any more.
Yes.
They belong on the existing question - unless the existing question is poorly asked and the new one is better asked.
New answers can, by default, be added at any time - and should, if existing answers are actually out of date rather than simply being old. (Many 10+ year old answers really do still apply.)
Asking the question again is not how the site is designed or intended to work.