The long fight to make Apple's iMessage compatible with all devices has raged with little to show for it. But Google (de facto leader of the charge) and other mobile operators are now leveraging the European Union's Digital Market Act (DMA), according to the Financial Times. The law, which goes into effect in 2024, requires that "gatekeepers" not favor their own systems or limit third parties from interoperating within them. Gatekeepers are any company that meets specific financial and usage qualifications, including Google's parent company Alphabet, Apple, Samsung and others.
It's RCS not RMS and Google didnt even want control of it in the first place, it's well documented Google has been trying to get US carriers to stop dragging their feet on RCS for a long time. They never did until Google literally went "Fine, I'll do it myself then"
AND RCS is an open protocol, nobody really has "control" over it, Google runs some RCS servers but if it disappeared tomorrow (Or you changed the defaults) RCS itself would run just fine on whatever including if Apple supports RCS
ETA: Also SMS is absolute trash, it's from the early 90's (it's older than me FFS) it doesn't really support what we want out of it media wise today, and what it does support it was forced to. It'll send "video" but it'll be completely unrecognizable. It needs to be put to pasture already.
It will be an easier sell if Google manages to get their proprietary extensions to RCS into RCS version 10, rather than only being supported in Google Messenger