Imo there's nothing actually wrong with necroposting. Replying to old posts can reduce the amount of repetitive posts on the wiki since users won't feel compelled to make a new post on a commonly talked about topic just because the last one was made over a month ago. Wookieepedia doesn't have a necroposting rule and things are just fine over there. I suppose the only real "harm" of necroposting is if you restart an argument that was over 2 years ago or something, but some people are fine with defending a post they made years ago and some find it annoying so to me it should probably be moderated more on a case-by-case basis than a blanket ban. Though at the end of the day, this is just one of those rules that both doesn't make complete sense but also aren't big enough of a deal for anyone to actually go to the admins about changing it.

But again, people can always opt out of following a post. And many posts (I'd even say a majority) don't have arguing.

Yeah, that's why I mentioned the case-by-case basis part.

And while I agree that by following a post, you are signing up to receiving notifications from it, most people reply to tons of posts per day and don't have a set timer telling them to find all the posts they replied to from the past month in order to unfollow them before someone necroposts, so it can still be annoying to them. Not that that means a blanket ban is the solution though.

What have I done?

Proving my point, you've sent an annoying notification to my notification box

Thanks.

So click the Unfollow option, problem solved.

Kinda late for that man

So do it now. See those three dots in the right corner at the top of the webpage. Click on that, select "Unfollow Post", and you won't get anymore notifications for the post while the others who still want to continue receiving notifications can continue to do so until hey decide they don't want to anymore. The same is true for Necro posts. Everyone's happy.

Just followed your advice for my own post why does fandom not allow us to delete our posts?

Confusion due to gaps in conversation? Who knows? I always found that peculiar myself. What I do for a post I want to delete is, if the time to edit hasn't passed, I just delete it and put a single period (since it won't allow an edit if its blank.