But the other part of that was that it would be constantly up to date.

They want to be the first result for "X in Y" and also have that be correct.

But if I ask how to write getter/setters in C# in 2009 and get an answer that represents the state of the art and accept it, that's it. That's pretty much locked in forever. Despite the fact that 14 years later, that answer should be very different.

But you can't "re-ask" the question. No one is going to "unaccept" the answer. And if anyone does edit the answer, it's not guaranteed to be correct anymore.

You get stuck with a corpus of knowledge that gets stale.