The most difficult parts of moderating on Reddit aren't the trolls or spammers or even the rule-breakers, it's identifying the accounts who intentionally walk the line of what's appropriate.
IMO only a human moderator can recognize when someone is being a complete asshole but "doing it politely", or trying to push an agenda or generally behaving inauthentically, because human moderators are (in theory) members of the community themselves and have an interest in that community being enjoyable to be a part of.
Humans are messy, and finding the right balance of mess to keep things interesting without making a place overwhelming to newcomers is a fine balance to strike that I just don't believe an AI can do on it's own.
Get you a show who can do both