What it does is not try to answer, but collect previous topics discussed by experts. Then answer the question based on the text, a far more reliable approach.
How does it qualify experts? I love the discussion here but if it turns to international nuclear strategy or the minutae of electrical networks (or presumably anything outside the regular wheelhouse) I notice that the quality goes down but the confidence stays the same.
Under the hood it builds and ranks the expertise of everyone in the network. That said, it doesn’t have knowledge outside the network, so if the network itself has low quality experts or no data, it’s going to give subpar results