Nobody who is trying to do things right, is going to use anything like that.
Oh, you're such a nerd. Not that's anything wrong with that! But the world doesn't work like that. Most of the people don't make app usage decisions based whether or not they're based on open standards / protocols, but on what kind of User Experience they get from the apps. In that sense, Whatsapp was FAR FAR better than the SMS they were competing with they started, back in 2009-10. The rest is history.