I think that you underestimate the portion of people just letting Youtube play videos in a continuous flow. They are doing the dishes, sewing, folding clothes, watching the entrance of the building... Stating the subject of the video makes a lot of sense for them.

I use DeArrow to remove clickbait titles and thumbnails, so indeed, I don't need that information to be repeated. I don't mind a few seconds at the beginning, what I hate is the person rambling about why they didn't post the day before and what not. That time multiplied by the number of viewers makes me wanna cry.