So even when answers are given, if they're not what parts of the community want to hear, they don't move on, but instead continue to press the issue. What good would that Q&A do, given this?
It depends on the reasons given.
E.g., If Larian doesn't implement a thing because they think the players want it implemented in a too-difficult way, then it is useful feedback to say "No, we think [this simpler way] is good enough." Changing our feedback to respond to Larian's Answers is not "pressing the [same] issue," but more like having an advancing conversation with Larian about improving the game.
Essentially, direct acknowledgement of things the community finds important and reasonable explanations for current implementations would be nice. Larian repeating things in multiple interviews isn't the same as Q&A interactions, because it doesn't necessarily mean they've taken our feedback into between those two interviews. It's often reads as the same answer just rephrased.
The community is also not a monolith. Obviously there will always be people who bring up dead subjects, but the goal is that enough people will stop pressing that the issue will die down. E.g., RtwP, once the biggest topic on this forum, is now mostly dead.
I also acknowledge that a large part of my reasoning is: it'd just be nice to have closer contact with Larian devs and get more insight into their process and thoughts. Do I deserve such interaction with them? No. Do I want it and think it'd be cool? Yes. Do I think they'd benefit from the happiness and feelings of inclusion a Q&A would bring, resulting in an overall less unhappy playerbase? Yes.