Completely inaccurate.
I talked with a content creator on a video which had over 40 downvotes counted through this addon, but through the YT backend it only shows 4.

I could understand if the addon counted LESS downvotes than what there are in reality, but it seems like it shows either random garbage or there's ways to manipulate the vote count.

Either way, it is inaccurate to the point of being completely useless.