Posted this as an example on #1898812: [policy] Deprecate forum module for removal in Drupal 11 → but droplet asked for a new issue to discuss it in its own right.
One issue moderating issue queues and discussion sites (whether using forum module or not) is the need to open new discussions from comments in the old one.
Drupal.org issues are a good example of this - someone brings up something in a comment on an issue that's out of scope but is worth discussing in its own issue (like this one!). Either they or someone else, then has to copy and paste the comment to a new issue form manually and link back to it.
More traditional forum software like phpbb allows (or at least allowed, I'm years out of date) moderators to take individual comments or sets of comments, then move them to a new topic with a new title.
On Drupal.org this could include things like moving different but related bug reports, or follow-up reviews, posted to a recently fixed issue to a new issue, potentially leaving the original comment with a 'moved to [link]' stub. The amount of times I've typed "please open a follow-up issue for that linking back to this one", or "I've copied X's comment to a new follow-up issue" is a lot.
https://www.drupal.org/project/comment_mover → is a 7.x module that provides the feature, it's been around since 4.x, I haven't used it since 6.x so don't know what the feature set is.
Note I don't strongly feel that this should be in core, but it's a feature that has broader application for community sites (including issue trackers) than the specific forum module feature of providing a bulletin-board-style index page.
Closed: won't fix
Idea
Not all content is available!
It's likely this issue predates Contrib.social: some issue and comment data are missing.