You can interpret these like and dislike interactions in two ways: in absolute terms or in personal terms. "Is this video good?" or "Is this video good for me right now?" We can debate what most users are trying to express* or if they are brigading, but it is mostly irrelevant. As soon as the platform stops showing everybody the same videos or at least random videos and it starts recommending specific videos to specific users then like/dislike interactions are a function of how well the algorithm is working, not some absolute measure of sentiment. Dislikes just indicate that the video was recommended to the wrong people. Netflix doesn't show the number of likes and dislikes and I haven't heard of anyone demanding that this change.
* The label "like" certainly suggests a personal judgment. On the other hand, the like/dislike placement and other feedback options suggest an absolute judgement. When I have (very rarely) used the dislike button it was more about a bad recommendation. Often the video wasn't bad in any absolute sense. In my experience I have to go looking for videos I truly dislike in some absolute sense. YouTube does occasionally ask me to rate a recommendation and there is a "Not Interested" option which are alternatives that are even more explicitly about recommendations. Unfortunately these are only offered before you even try to watch a video or if you are very intentional about returning to your recommendations feed and finding "Not Interested" in the three dots menu.