The problem is that carriers are terrible at this kind of thing. For example, here in Canada, Rogers, Fido and Bell support RCS. Rogers/Fido use Google's Jibe

The problem is that carriers are terrible at this kind of thing. For example, here in Canada, Rogers, Fido and Bell support RCS. Rogers/Fido use Google's Jibe infrastructure, but Bell uses Samsung infrastructure. The result is that if you're on Fido, you can't send text messages using RCS to your contacts on Bell because there's no interoperability between their infrastructure and Jibe. How insane is that?