It can be implemented directly, though. Like as a site feature showing a message above the comment form, not as a bot making posts.

Honestly I think that's just a failing of community ethos. It'd be nice to bring back the expectation that people make the bare minimum attempt to check the rules of a community they're trying to participate in, and let moderators just assume that everyone has read the sidebar rules. If you haven't, and you break a rule by accident... well, tough luck, you'll get the same treatment as everyone else. Next time, read before posting.

Ask yourself, did automod actually help that?

Brave for your to assume that people read the automod comments. I quickly learned to igbore it, it was a second nature for me to scroll past it.

Than again, I never had any serious troubles with my posts or comments being moderated. Perhaps I was just not being a jerk which seems to get you very far (not already if course as some Reddits were nazis about their silly rules).