What’s the difference between that sort of topics and news groups or mailing lists (with archives)? If I want information on something, subscribe; if I don’t want information, unsubscribe: I can always follow/search the archive (or read digests)
The archive on NNTP is a first-class artifact that you can interact with in your newsreader via NNTP. You can do things like reply to old threads.
The archive on a mailing list is a second-class artifact, typically hosted via HTTP, and usually people don't care about the quality of the archive's UX.
The structural organization on NNTP is also a first-class artifact that everyone can refer to. A mailing list will go straight into everyone's inbox, with all their other mail, until they filter it away.
It's a second level of organization/subscription so that you can have more fine-grained control over how much you get spammed.
News groups and mailing lists don't scale super well, in that, when you subscribe, you then get sent everything. Maybe not terrible for the 5-10 emails a day from my kid's playgroup's email list, but absolutely awful for trying to keep up with a team of 100 people.
In a newsgroup, you don't get sent anything. You can go to the group and see what's new. If there's a particular thread you're not interested, tell your news client to ignore it; if there's one you're particularly interested in, tell your news client to watch it:
But the solution is exactly the same: create a new mailing list or newsgroup under the sort of circumstances where you’d add a topic to a forum or a channel in a Slack workspace. Open source projects, for example, will have foo-announce, foo-user, foo-devel, etc.
Or use digests, mail filters/folders and a convention for tagging message subjects.
So, that's the top level. The 2nd level would be more analogous to individual email threads within those groups.
Once you get down to the individual conversation level, the fine-grained management bits you talk about are not good UX, they're band-aids for dealing with bad UX.
Well, whether they’re good or bad UX depends on assumptions about whether the second-level categorization is more meaningful organization-wide or on a user-by-user basis.
2. Contextually-scoped lists. If a topic is of limited concern yet intrusive, split it to a separate list. Moderation and management may be necessary. Technical teams should be scoped correspondingly. 100+ team members is excessive, 3-15 far more typical.
