Primarily because of interoperability. There is still no messaging format as ubiquitous as SMS, and it's a constant annoyance to me that my friends on Android d

Primarily because of interoperability. There is still no messaging format as ubiquitous as SMS, and it's a constant annoyance to me that my friends on Android don't receive my (photo/video/group) messages as easily as my friends with iPhones do. Sure, everyone could switch to one of the third party services out there, but it's been years and they still haven't. So I'm all for establishing a new baseline that doesn't try to do everything and just builds on the foundation already existing in SMS.