EDIT: @mindbleach@sh.itjust.works shared something that might help to circumvent this shit:
Contained in these parentheses is a zero-width joiner: ()
Basically, add those to whatever you feel that might be filtered out, then remove the parentheses. The content inside the parentheses is invisible, but it screws with regex rules.
Yes, YouTube comments are a cesspool and reading them makes my IQ drop ten points each time. It's probably already in the negatives by now.
But we could/should exert some pressure on youtubers mentioning Reddit. Such as Francis John. Encouraging the Reddit→Lemmy movement in the same way as the Twitter→Mastodon one, for roughly the same reasons (except that instead of Musk, you got someone who praises Musk in reddit. Like, not even the piece of shit, but the fly around the piece of shit).