it’ll work just like SMS does now
I agree with this part of your statement 100%.
It will work POORLY.
Whether it’s in the same app or simply a different colour like SMS is currently, it’ll be a half assed implementation, designed to segregate your iphone and android friends.
Got an existing iphone group chat? Bet you can’t add an RCS participant to it.
Create a new RCS group chat so you can include everyone? Bet it’s missing features that you’d get in imessage.
Receive a high resolution video from a friend via imessage? Forward that to another friend via RCS and they’ll receive 5 blurry pixels.
And throughout all of this, apple will blame the RCS protocol and say “We’re actively working with GSMA to improve RCS”.
No one trusts apple for the very simple reason that they have a habit of saying the quiet part out loud: Tim Cook Says ‘Buy Your Mom An iPhone’
Windows XP is basically firmware at this point, and has been for over a decade.
Lots of proprietary hardware that works perfectly, will not work on newer versions of Windows due to lack of drivers.
I see it constantly in factory situations with scales, scanners and robot controllers, it would only be worse for million dollar x-ray machines.