There is an article. It contains a typo. Someone mentions it in a comment. The comment is upvoted as helpful. Author fixes the typo. Now there is a no-longer-useful comment in the discussion, sometimes with replies (the author saying "thanks, fixed", etc.). Sometimes it sits at the top of the discussion, if it was sufficiently upvoted.
If I try to avoid this, I send the author a private message. This does not clutter the discussion, but the disadvantage is that other people don't see me doing this -- so they are likely to also send private messages to the author, and maybe someone will make a comment anyway.
Downvoting the comment gets it out of the way, but it's not fair to the person who made it. We should encourage reporting typos, definitely not punish it.
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My proposal is to make a new functionality that approximately means "this comment was useful at the moment it was made, but it has outlived is usefulness". Available in the three-dots menu in the upper-right corner of the comment.
A comment can be marked like this by the person who made it, or by the author of the article. (Or by the moderators, of course.) A comment marked like this will be moved to the bottom, regardless of the sorting mode, and will by default appear collapsed. (Maybe also displayed using a different color.)
Unlike retraction, this has no impact on voting, etc. (I am not 100% sure how retraction works.) You can still read the comment, even upvote it if you wish. It just doesn't get in the way. Also, semantically, there is a difference between "I no longer support this" and "this is no longer relevant, but it was when I wrote it".
(If you get a notification on an account you no longer check, that doesn't really help.)
Hm. I think you have a somewhat more optimistic view of this than I do.
I do not believe that "a (failed) attempt to fix an issue" can be that easily distinguished from abuse.
It's not so much "this comment reported a typo". It's things like "step 6 of your argument doesn't follow from step 5" hidden and the post updated with something that doesn't actually resolve the problem.