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*.
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?