It doesn’t matter if the most upvoted comment is pro or against subject in discussion. All that matters is bolstering a comment that is minimally compatible with participant’s thinking and making it win against the opposite argument (competing and most voted one).
So it seems that the most satisfactory comment (for most readers) doesn’t really matter at all. What matters, before anything else, is visibility of an opinion that somewhat aligns with one’s thinking, rather than writing or finding the most corresponding comment for that subject, fully compatible with reader’s perception.
The big problem I’ve seen with “Active” as the default post sort is that you occasionally get year old posts suddenly get comment-bombed when someone scrolls too far and upvotes it. Suddenly that year old post is marked as active again, so it’s in everyone’s feed. And most people don’t even bother checking time stamps before commenting, so you suddenly get a flood of comments on your year old post.