Eh, you’d still have the green bubble problem. Since RCS, even Google’s proprietary layer on top of it, can never have absolute feature parity with iMessage (unless Apple is legally prevented from updating iMessage or forcibly required to get all of its iMessage features backported to standard RCS), you’re going to have an issue where the sorts of chat features you might want to use aren’t available with all your contacts, so you’ll need a visual indication of that. And RCS fallback would probably remain green bubble (perhaps a slightly different shade of green) because “green bubble” means “not all features are supported”. I can’t stress this enough because some people (even on this thread) do push for RCS, thinking that it’ll somehow end the stigma against being a “green bubble person”. It won’t, even if group chat is a lot less painful. If your friend group heavily uses, say, iMessage applications, RCS isn’t going to prevent you from being left out of the loop.
(As an aside, of course, original SMS messages on the iPhone were green. Back then, green was just the branding color they used for Messages. Heck, the app icon is still green, even if the UI branding color is blue these days. So really, it’s not that green means you get less features but that blue means you get more features.)
Who’s talking about feature parity? Who gives a rat’s ass about bubble color. This is about the next gen after SMS.
Currently if you’re on an iPhone using Messages and someone sends you a message using RCS you will never see it.