I know a lot of Ao3 ideas get shot down unless it's liking multiple chapters (in which we all say "Me too, kid. Me too"), but hear me out on two ideas.
Not like the stats for each user, but a site wide tracker. You can see how many fics are on the site, how many users are on the site, the most used tag, the ship with the least works on it, et cetera.
Why should we add it? Because numbers go brr and so we can learn more about this coveted digital Library of Alexandria.
And there's no cons to adding this as far as I know.
Remember that fic that had every fucking tag known to man (all I remember about it was that the media was most likely a Chinese sit com or visual novel), crashed the site multiple times, and lead to the 75 tag limit? Or maybe the time that someone forgot an important tag like non-con and left you speechless
Well, ever since some purists started bitching about better moderating as if Ao3 was not made because of that specific bullshit and heard the horrors of someone forgetting to tag something important, I had an idea for a comprimise.
It's simple, they check your fic and check your tags to see if they match up. If there is a tag that needs to be added, they add it. If a tag is not mentioned in the fic, they remove it (this mostly applies to wrangled tags, fandom identifying, shipping, and the big three [Violence, Non-con, and Incest])
You will get a notification explaining what happened if the mods change your fic's tags, and it usually doesn't mean you're being punished so long as you aren't purposely being a dick and tagging everything but the kitchen sink.
Pros: Fixes the tagging issues, makes it easier to find fics you like and sift out the ones you don't.
Cons: More stress on the moderators who are already working overtime.
So in conclusion, Ao3 could add site stats and/or tag moderation to make the site just a bit better in my opinion
If anyone has questions or want to give their two cents about my ideas, go ahead.