YouTube may not penalise your channel's exposure for dislikes if you are still getting plenty of watch time and engagement, but they do use those dislikes to gauge personal interest. That means there's a higher chance that the user who disliked your videos will not get your content recommended to them in future.

Do dislikes on YouTube do anything?

Long story short – dislikes do affect the ranking algorithms of this network, but not in the way that you think. ... So, whatever they do, even if they hit the thumbs down, this action will count in your ranking as a method of interaction.

What happens if you dislike a video on YouTube?

Reports have suggested that a video with a high number of dislikes — that outweighs the number of positive likes — is less likely to be recommended, and could therefore hurt the creator's channel.