RCS is an open standard. However, on Android you can only use it with Google chat. So android stops any other apps from using it. Nothing to stop you making your own phone from scratch and adopting it.
Samsung messages app also supports RCS, depending on your carrier, though? It’s super fucking buggy and frequently switches back to sms so I still switched to Google messages, but it does technically have it.
RCS is an open standard. However, on Android you can only use it with Google chat. So android stops any other apps from using it. Nothing to stop you making your own phone from scratch and adopting it.
It’s incredibly stupid, I know.
Samsung messages app also supports RCS, depending on your carrier, though? It’s super fucking buggy and frequently switches back to sms so I still switched to Google messages, but it does technically have it.