If you genuinely don’t understand the limitations of SMS or the differences between it and RCS, then I highly suggest you check them out. You may learn something.
SMS, I can send and receive messages, I don't need anything else.
I know the differences, RCS can send higher quality video, photos and whatever other rubbish people want to send, which is not possible to send with SMS anyway, that is MMS.
Suits me, I don't want people to send me that stuff anyway.
RCS also have encryption, but not always, if using the carrier version of RCS, they may not support encryption. Not that I have messages that need encryption.
But RCS is not going as planned, is it? RCS was supposed to be supported by carriers, just like SMS, but it has not happened to any great amount. Google is the middle man so to speak in the majority of it. The GSM Association wanted networks to support it, but it seems to have changed to a Google thing because without Google sticking it in their messages app and providing the service, RCS would be dead in the dead in the water.
People seem to use Whatsapp for messaging these days, not that I do, again, I have no reason for a service like that.
In the U.K, only 2 networks support it, EE and 3 and 3 is now part for Vodafone, so I doubt it will stay for long and on the Iphone RCS encryption is only beta on those networks.
So I know what RCS is and what SMS/MMS is, I use a app for SMS/MMS that don't support RCS, I don't like Google messages app and since i have no need for RCS, I see no reason to change.