This, in a nutshell. It's also reinventing the wheel. Take Slack, for example, which is just IRC with a fancy interface and horribly centralised infrastructure, monetised to death. You could do exactly the same thing with a well tended XMPP server and a few plugins, minus the irritations.
Personally, I don't see the appeal of these newer communications portals. It just feels like the basic transfer of information these days has to be dressed up in useless chrome and flashing ads before it gains any legitimacy at all, so much so that the information itself becomes secondary, almost an afterthought. People who not only don't need but cannot use all of that have been quietly sidelined.
All of that is before we even mention the intrusive monitoring and Big Data wallahs.