How I wish all my communications could be funneled into just one channel: e-mail, chats on different media, even phone calls, etc. All registered in just one app so it stays coherent and I don't have to browse 7 apps when I'm looking for something. It's far more of a legal problem than a technical one, and it's a *shame*.
There used to be something like that for IM called Meebo. It's a great idea, but do chat systems like Facebook allow third party apps?
I don't see anything changing until messaging services are compelled by law to interoperate with 3rd party apps. This mess is there to last.
What if people around us use the same communication channel ? I mean if I setup a Mattermost instance and I convince my friends and family to use it (separated by example by differents teams) all communication (text, audio and video) can happen in the same place !
Assuming you get all colleagues and friends on your Mattermost (good luck with that :p), will you decline friendship with people who only use regular SMS?