Yeah its kinda harsh and a blunt instrument of control here but just disabling comments is easy and quick.
It'll make commenters mad but most YT comments are terrible in general and most of the YT content creators seem to feel its mostly pointless to even bother trying to read most of them.
Youtube is as much about social interaction as it is about the videos. You don't build an audience by disabling all comments.
Edit: Also, comments are a form of engagement that Youtube uses to judge if videos are worthy of featuring or recommending to viewers. So channels would be punished by Youtube's shit algorithms if they disable comments.