I'm a volunteer moderator for a good-sized Twitch channel, and hang out with the mods for the affiliated discord (about 45,000 people). I might be biased, but I think it's one of the best moderated communities on the Internet (or at least the RPG sphere, which is where these communities live). Our attitude is that there's a whole wide internet where people can be pieces of shit and post whatever they want, but in order for the space as a whole to not only be welcoming, but successful, we have to engage in a kind of curation. Sometimes that means that a first-time chatter gets an immediate ban if they're starting off really weird. Sometimes it means banning someone whose been active and around for awhile because they're causing others to be uncomfortable.
The point of bans is that they are not executions -- they are a strong first step in community management. On Twitch, we read and discuss all of the unban requests. If someone seems sufficiently apologetic, admits wrongdoing, or otherwise explains their behavior, we often lift bans, depending on the severity of the infraction. Obviously, bigotry is an instant and irrevocable ban.
My point is that moderation is a key part of any online space, and imo should be deployed fairly liberally in order to have a growing and successful community