I've been using the Return YouTube Dislike extension[0] for a couple of weeks now and it seems to be working surprisingly well (due to the relatively large user base probably, surprised it hasn't been mentioned here). It uses a combination of dislike data of other users of the extension combined with data from older videos which still have dislike count accessible through the API.

And yeah, hiding the dislike count was an extremely weird/annoying move, given that it was a good quality indicator which is now completely gone. It doesn't matter if a video has 1M likes if it has 3M dislikes, in which case it probably sucks. Nor are you misled to believe a video with only 3k likes is bad if it doesn't have more than 22 dislikes.

As with everything you should keep context in mind. For example if you're watching a video on a political topic (or by a controversial character) then the ratio will be more even, even for high quality videos. But the point is: Give the user the information, don't assume they are dumb.

[0] Links for Chrome/Firefox/etc: https://returnyoutubedislike.com/install

Mine never disappeared, only the dislike count.

Have you downloaded the extension that brings that back?

how is it worse? I had the same initial reaction to the announcement of the change but I can't say I've noticed a difference.