Moderation is keeping people on topic of the forum, killing spam, trolls and sockpuppets, removing abuse and so forth, and trying to keep things on the rails and civil. Including banning trouble makers. Rather like dang does around here. That's not censorship, it's attempting to avoid anarchy. Neither is limiting the range of topics the forum or platform wants. Standards and extent will vary depending on the aims of the site.
Censorship is suppressing a view, even if it follows the standards and allowed topics of the forum. Legal censorship is a little more complex as standards vary between countries.
Having a post removed because it's spam, abusive or is off-topic is not censorship, which was the point the GP was erroneously trying to make.
Soft-censorship and derailing is done on purpose to censor certain topics which go against the establishment status quo. Reddit is fertile with such examples. If someone is making a comment which does not bode well to those in power, it is common for the thread to be sunken with low-class behavior and baits in order to shut down valid discussion by forcing an emergence of rule-breaking content.
That is a far more greater threat.
How do you propose to mitigate that?
That's exactly what censors say
The internet and Usenet did OK without moderation until Eternal September and the invention of SPAM, when internet culture started to die. RIP. Before that a new arrival was expected to figure out netiquette, and everyone else would behave accordingly.
Ever since then there has been an fairly steady slide. The arrival of astroturfing corporate and special interest groups, trolls, and platforms that assist the amplification of effect by actively seeking to avoid any moderation has just intensified things. Those places without moderation deviate to lowest common denominator with astounding speed. We've seen it time and time again, and as a result many sites have closed down their discussion areas entirely. See reddit subs with and without active heavy moderation. Moderating does not rule out anonymity, nor should it.
Without moderation commercial interests, political groups and trolls will ultimately ruin all locations that attempt to allow reasonable discussion as it is not in those group's interests to see a virtue in being virtuous.
The few places left where you can have reasonable discussions, including on controversial topics, are those that moderate hard. They don't censor.