The people who run almost every platform that has user-generated content of any kind share an assumption that it's necessary to have moderators remove uncivil content. This assumption is mostly wrong.
My thoughts about this were influenced by Shamus Young's "Philosophy of Moderation" where he argues against having explicit written rules. His article is great, but my position is more extreme than his. Hereafter, I'm going to use the word "censorship" instead of the euphemism "moderation".
First, I argue against the necessity of censorship. Muting systems are not much less effective at achieving the benefits. If someone's persistently an asshole, more people will block/mute them until no one wants to engage. It isn't as instant or sweeping a consequence as censorship, but that's not a bad thing - it can allow for more granular consequences rather than a moderator having to decide whether to delete something or not.
Next, I argue for drawbacks of censorship.
Moderator intervention drastically increases drama. A person censored by a hand from above is not going to change their behavior; they're more likely to become very hostile to the moderator and pessimistic about the platform in general. The threat of "consequences" is actually weakened by its exercise because being shown that you can't say what you want to on a platform makes you question whether you even want to be on it.
And it's not just the censored user that gets bitterer. Anyone who wasn't responsible but liked the censored content or just thought censorship was an overreaction will also be offended.
Another drawback applies when moderators are also normal users. Power imbalances are never good for interpersonal relationships; they always breed contempt over disagreements, since in any disagreement that gets heated, there's the implied threat of moderator action.
Finally, censorship takes human time. It's costly. Muting is not as costly because there's no issues with review or appeals or accusations of unfairness; each person just makes the decision for themselves at the click of a button.