Yeah, it's pretty awful tbh. I generally recommend disabling RCS, after learning a lot more about it - it feels like a hostile grab at global messaging at this point, heavily entrenched by telecom agreements. Use Signal or something instead.
Initially there were some promising details planned, but much of it hasn't panned out, and plus now it's Just Google™. Like, roughly everyone has heard that RCS brings E2EE privacy, right? Would it surprise you to learn that it was only added to the spec around a year ago, and nobody has it implemented yet? Google has their own thing between Google users, Apple has their own iMessage-only thing, and they both drop crypto when you cross the streams because it isn't in the spec. And neither is practically auditable (allowing auditing is part of the spec btw - have you seen that UI?).
And that's before even touching on the utterly massive amount of the spec that's clearly designed for businesses only, to send you highly customizable interactive UI. Which you can't use as a person. Or build your own app for. https://developers.google.com/business-communications/rcs-bu... / https://rcsforbusiness.google/
It just does not smell good. It's not in our best interests to let it win.
Yeah RCS always has been an embrace extend extinguish thing. The carriers were super pissed to lose their SMS revenue to WhatsApp and iMessage so they came up with this shit to be an active partner in the loop again, and they can bill for it again. Consumers didn't fall for that and it died off.
Unfortunately Google revived it but it's a very poor standard for interoperability. Not only because the lack of true E2EE in the open spec but also because you need to be a blessed party to run an RCS server and communicate with others. You can't run your own or choose a party you trust. It's either your carrier if they bother to run one, or Google.
It's just another power grab. Don't fall for its 'open' guise. They want you to use it so they can make you dependent and lock you in again. There's nothing open about it. If you want privacy, use signal. If you also want an open and federated network, use matrix or xmpp with OMEMO.