They are also the only RCS supplier on Android. A random messaging app can’t simply add RCS messaging functionality.
You are correct that an app can’t directly implement RCS but it can support it. RCS is implemented by the carrier, not by Google or any other text application.
RCS is an open standard that any carrier can implement to replace SMS/MMS. The only thing special that Google does is on top of RCS is provides E2E via its own servers for handling messaging. The E2E isn’t a part of RCS, though it should be IMO. Regardless, Google doesn’t ‘own’ the Android implementation because it isn’t a part of Android, other than it can support the carrier’s implementation of RCS.
Last I had looked into it, although the standard exists, they use their own servers and are not compatible with other rcs implementations
They are also the only RCS supplier on Android. A random messaging app can’t simply add RCS messaging functionality.
It’s not really much of an open standard at all, in practice.
You are correct that an app can’t directly implement RCS but it can support it. RCS is implemented by the carrier, not by Google or any other text application.
RCS is an open standard that any carrier can implement to replace SMS/MMS. The only thing special that Google does is on top of RCS is provides E2E via its own servers for handling messaging. The E2E isn’t a part of RCS, though it should be IMO. Regardless, Google doesn’t ‘own’ the Android implementation because it isn’t a part of Android, other than it can support the carrier’s implementation of RCS.