I got you point but this can also be a big problem since there’s no interconnectivity like we have…

I got you point but this can also be a big problem since there’s no interconnectivity like we have on email. It doesn’t matter your provider, App or country you live, all I need is your address and you’ll get all my messages. As for instant messaging, we have to agree on a medium beforehand. And there’s even the absurd situation we may have to have the same device if one is trying to contact the other via iMessage.