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. I think this assumption is wrong.
First of all, I'm going to be using the word 'censorship' instead of 'moderation'. This might seem unfair because 'moderation' suggests something most people view as necessary and good while 'censorship' has a very sinister ring. But every power moderators have is a form of censorship. If anything, I think moderation brings out the ways in which most people think censorship is good but don't want to put it that way; moderation is really a euphemism for censorship.
My thoughts about this were influenced by Shamus Young's relevant article where he argues against having explicit written rules. His article is great, but I think my position is more extreme than his.
First, I argue against the necessity of censorship. I think muting systems are not much less effective at achieving the benefits. If someone's persistently an asshole, more and more people will block/mute them and no one will want to engage. It isn't as instant or sweeping a consequence as censorship, but that can also be a good 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 negative about the platform in general. The threat of "consequences" will actually get weaker 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 - I've experienced this myself.
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 remotely heated, the implied threat of moderator action surfaces.
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.
Now obviously I'm not saying no platform should ever censor anything. My arguments are mostly against censoring toxicity. Some cases my arguments don't apply to:
Harmful false information or linking to malware/scams.