There's some textual detail in the video that seems important to his presentation which could be missed at 2x/1.5x and I like listening to things at normal speed. Listening any faster would probably make his speech affectation even more deeply annoying. It's just a terrible presentation.
When you're knowledgeable and your content is quality, I don't understand why you'd need to dress like a cat during the videos. Is it a gimmick for attention? If so, is the assumption that those interested in DNS somehow intersect with those that enjoy seeing 30+ year old men dress up like a cat? Maybe I'm overthinking this - the guy does seem to have quite a few views, so apparently it's working for him.
https://www.youtube.com/watch?v=4ZtFk2dtqv0