Separate issue: on the internet, it is near impossible to tell good faith discussion from bad when a comment makes any kind of snarky tone or logical fallacy. And there is so much trash on the internet that it can be easy to delete really shitty low effort comments - you may imagine some young troll getting their kicks on stirring things up. But it may be just as likely they're just someone with some bad ideas who can't do rhetoric well.

And so when you delete their comment, you think "yes, cleaned up a troll" while the person who tried to engage in conversation just sees censorship.

Upvotes and locking comments are better than deleting or banning. Again, Slashdot has the best moderation and filter system.