Sometimes there are comments or debates that aren't mindless, however, it depends what you're watching on YouTube. The mindless ones I ignore because I know there's no sense in getting involved and worked up. The comments aren't necessarily there to make someone feel sad, they're just mindless nonsense and the way I view it, getting involved in the mindless nonsense is only going to feed it and by that time, you've got yourself in a spiral of nonsense.

Lots of it probably is stuff people wouldn't say to another person's face, and so some of the vile stuff is merely confidence-boosters. The individual is confident already at that point and so attacking them is possibly going to annoy them, and so be prepared for a retaliation composed of anger. It's the same as when someone in real-life gets an award and is very happy and confident, then someone makes a snide remark to them. That person will get immense anger towards them. It's no different on youtube.