Over-moderation will kill Lemmy instances. One of the reasons Reddit became as big as it did is due to very light-touch moderation verging on “absolute freedom of speech”. It was refreshing and ‘alternative’ compared to the increasing sanitisation of the Internet.
That’s the sub not the website, over moderation is a feature of some subs, just like lemmy instances. Just like reddit, if you don’t like it create your own, unlike reddit you can set an overall tone to your instance.