Oh, even better.

It really must be enormously difficult to release an app using RCS on the iPhone as Google ONLY has released Google Chat and not Google Messages. Google Chat is good enough for chatting with my Android friend, though. Not sure what “Google RCS” would add to it (if anything).
I didn’t say it was exclusive, but I can see how someone would read it that way. It should have been “Google RCS” is a thing at the US carriers because they individually DECIDED it would be a thing. Without the carriers, there would be no “Google RCS”. Additionally, all the US carriers have determined that they are fine with “Google RCS” working between Android phones only. That’s likely NOT where Google wishes they’d left it, so now it’s Google, by themselves, trying to make a thing happen that the vast majority of carriers worldwide rejected awhile back.