@Gargron New features that would make Mastodon really attractive for that would be:
1. The ability to create a public or private “community” on a given instance, which a user on any instance could join (under the control of that community’s moderators) and post.
2. Longer-form posts composed in Markdown format, which would only show a snippet in the regular timeline but could expand into something bigger (taking up 2 columns in the regular UI).