Um, you keep using the phrase “new standard” in relation to RCS. Nope.
RCS is a 15-year-old standard that Google has been hawking for years. It’s old tech, not all that flexible, and adopting Google’s port of that standard means buying into a Google proprietary world. Apple would be nuts to do that.
And the whole blue bubble/green bubble angst trope is kind of silly. In Europe, nobody uses anyone’s text messaging anyway: they use What’sApp, which is IP-based, encrypted and relatively modern, As is the blue-bubble mode of iMessage. And no, I don’t use WhatsApp, as I trust Meta even less than Google.
Finally, as frequently as Google retires applications and leaves user populations in the lurch, why would anyone trust Google to do this right?