The YouTube dislike button existed long before modern Reddit culture (lol) did. If anything, the Reddit vote system is quite different since it does not really

The YouTube dislike button existed long before modern Reddit culture (lol) did. If anything, the Reddit vote system is quite different since it does not really show the absolute number of up and down votes, and they are even slowly moving towards phasing out the % of up/down votes display counter on posts. It never was available for comments in the first place. Plus, dislike also boosted engagement and could be good for your video, so again very far from the Reddit karma system.