This is why I don't buy Google's bad faith shaming of Apple for not adopting RCS. The current version of it that people are using on Android isn't even a "standard" by any normal usage of the term, it's just another Google messaging service. No one can make their own app, and there's barely any carrier adoption, so Google is basically running the whole network.
Does this mean that now if you send a message to someone from an iPhone that doesn't go through iMessage, it will instead go through Google's servers? Sure the service will hopefully be better than SMS but at the cost of giving Google the keys to pretending they're a "standard."
Excellent. The next step is for Google to release a free and open source way for Android developers to build apps that send RCS messages. Currently, the only messaging app on Android that fully supports RCS is Messages by Google, which is closed source and requires Google Play Services to activate RCS features.
Also, end-to-end encryption is not part of the RCS specification, but is a proprietary extension to RCS that Google has made exclusive to Messages by Google.[1] This feature should be made open and added to the actual RCS specification so that Apple and other vendors can make use of it.
(Notes: There is a proprietary RCS API which Google only allows Samsung apps to use to communicate with Messages by Google.[2] Verizon has an app called Verizon Messages or Message+ that uses RCS to some extent, but this is an incomplete implementation that only works on Samsung devices on the Verizon network with no cross-carrier compatibility.[3])
[1] https://arstechnica.com/gadgets/2021/06/google-enables-end-t...
[2] https://www.xda-developers.com/google-messages-rcs-api-third...
[3] https://www.verizon.com/support/knowledge-base-222792/