Its less that nobody at Youtube tried to solve the problem but more that it was never a business priority in the interests of the bottom line to solve this problem in a nuanced way.

For Youtube, these kinds of comments threaten to alienate advertisers. Comments only have a miniscule impact on viewer retention and engagement, so if the actual business is threatened by comments you just get rid of the comment system.

Saying it's not a "business" priority is the same as saying that Youtube isn't trying, just with more words. It's also subject to the same survivor bias because we don't know the "business" investments into community and moderation.