Why should anyone care about RCS? The trend has been to get everything into data instead of carrier owned services for two decades now, we don’t need another SMS (it will likely always be a fallback). What we should move onto is a carrier and device type angnostic universal standard protocol over TCP / QUIC like XMPP or Matrix, with SMS as the backup.

When you get a phone you can get an phone system account and a telephone number already. Modern apps in the Google ecosystem should already recognize you are already signed in with Google and sync your contacts. Since almost everyone is already in the Google ecosystem, if Google supported it they could have extended their XMPP implementation in Hangouts to allow messaging directly via XMPP to those contacts and SMS for anyone not yet in the system (similar to how Signal did, Apple does, and Google does now with RCS). Unlike Apple, since its just XMPP, users can still add friends and be added by friends on other XMPP servers (ex. their ISPs, their own, or a third party). They could have supported or jumpstarted a new very simple open source alternative app for that portion for AOSP if the EU complained. Eventually Carriers could have supported passthroughs for those still on feature phones and other users of SMS to use the number@carrier accounts to hit XMPP users with generated SMS numbers for non-SMS users (pushed either by business necessity or part of a government / teleco org like GSMA staged removal of SMS and telephone numbers). It’s all data at the end of the day.

Instead, they developed a whole new protocol to fluff the telecos and keep the now badly managed telephone number system even more necessary allowing spammers and allow the problems of legacy SMS to continue.

Apple, Google, and Samsung should all be shamed for not supporting fully open protocols and necessitating dependency on user harming stacks.