Not sure if they matter but I have about 12 videos on my channel and my like percentage is about 90%.
Do dislikes matter (I heard too many will push down from recommendations) and does it get better over time? They bother me almost more than view count lol.
They don’t matter. In fact, they actually help to some degree, because they show that the viewers are engaging with your videos. They used to negatively affect videos pre-2013, but they don’t anymore due to how easily they are manipulated.