But doesn’t that extension just assume dislikes is some proportion of likes (1/3 comes to mind but I’m not sure why)? The whole point of dislikes is knowing ahead of time that the video is a pile of shite, for example if it’s got 20 likes and 200 dislikes it’s probably not worth bothering with. But if it’s got 20 likes and, say, 7 dislikes based on dislikes=likes/3, that gives you no useful information.

Now if that extension queries some API that returns the hidden 200 dislikes, THEN it’d be useful.