These multi-communities. How would they work? They’d have to be curated by the user - which is a dead end since 99% won’t bother. Or else curated by someone else which leads to politicking about who’s listed and who’s not.
And what happens when you go to post? You have to pick one? And worry about who will see it and who won’t? Again, most users would find this burdensome.
Or it could just be like a hashtag and go out into one big conglomerate community. Who hosts that? How is it propagated? How does moderation work?
I think communities curated by a number of people passionate about each subject is just the best way for forums of this nature to work, realistically.
If a community gets too bad, they can and will be fractured and eventually one dies.
Ideal? No. Just what works best.
Multi-communities is a feature we need though. I just don’t think they’re a solution.