That doesn't bother me really, I'd be fine if the youtube comments did not exist at all.
I actually love the youtube comments you see on old music videos--they are almost entirely aging people reminiscing about music from their era, recounting stories about people they knew and experiences they had while listening to the music. Drop into the comment section for the song "80's Ladies" by KT Oslin if you want to feel a bracing sense of your own mortality.
I block them with uBlock. They are very rarely contribute anything to the video.