Let me add to the question: Any such network that is actually used by more than very niche peer groups, that wouldn't be just as well served by IRC, Slack or Matrix or Discord?
You list two open chat protocols and two proprietary services based around rich media chat. Despite bells and whistles, these are all fundamentally about chat and presence.
A contemporary social network implies a profile, an asymmetric social graph between users, personal status history, an aggregate friend feed, and a content management system where users can upload and share media.
Rich media chat apps can approximate some of these usecases but they aren't the same thing.
With respect, I disagree; IRC with a bouncer and a bot would serve those functions handily. The other chat platforms also have mechanisms for groups, sharing files and metadata, and creating social "graphs" via the use of channels. I submit that they're no worse than the options listed.
What makes Twitter better than the niche social graph/network tools presented?
