I was disappointed that YouTube had removed the display of dislikes on videos, apparently as a response to people expressing their disagreement with government and NGO content, which some consider to be propaganda.
Dislikes serve at least two important functions. Firstly, they are a form of direct democracy. They provide an extremely low effort method of giving feedback to the nature of content, or a proposed policy. This provides an important backchannel for those whose voices may not be carried across traditional channels.
Secondly, dislikes provide epistemic insight. The number of dislikes on a video can illustrate whether content is generally trustworthy. If content may be fraudulent, shilling, or spammy, the dislikes count immediately alerts one to be mindful, without needing to sit through a lengthy video and various ads.
Removing dislikes will make it harder to fight back against misinformation and demoralization, two of the greatest social problems in our digital lives today.
Luckily, there are some ways around the dislikes issue, at least on desktop. I can recommend this plugin for Chrome and FireFox which restores the visibility of dislikes on videos, at least until YouTube updates their APIs.
Hopefully, if as many people adopt it as have installed adblockers, they may eventually relent.