is not rcs simply another locked down standard under the thumb of google, which they have decided to limit and block on rooted devices in the past?

correct me if im wrong ? but this all seems like a freight train of no good barelling in. google propoganda has won out and we’re swapping one gatekept standard for another.

I believe that RCS is a specification maintained by the GSM Association. That’s not to say Google is not a member (they are) and has a strong influence, but Google doesn’t own the standard either

Last I had looked into it, although the standard exists, they use their own servers and are not comparable with other res implementations

They are also the only RCS supplier on Android. A random messaging app can’t simply add RCS messaging functionality.

It’s not really much of an open standard at all.

They are also the only RCS supplier on Android. A random messaging app can’t simply add RCS messaging functionality.

You are correct that an app can't directly implement RCS but it can support it. RCS is implemented by the carrier, not by Google or any other text application.

RCS is an open standard that any carrier can implement to replace SMS/MMS. The only thing special that Google does is on top of RCS is provides E2E via its own servers for handling messaging. The E2E isn't a part of RCS, though it should be IMO. Regardless, Google doesn't 'own' the Android implementation because it isn't a part of Android, other than it can support the carrier's implementation of RCS.

No app on Android can use RCS yet, other than Google messages.

Not true. Both Samsung and Verizon messages uses RCS, so long as your carrier has implemented RCS.