3/3
Mastodon I use for conversations. Like this one.
That said...
I keep my Mastodon connections to just a few in number and delete people if they drown out everyone else.
This creates a nice informal community for me based on nothing in particular except that I like the people in it and find them interesting.
If I wanted to replicate this with a different group I'd need a different environment (or another copy of the same environment). Each group would be different.