the frustrating thing about RCS is that so many android users don't even use it because they have purchased a phone that has a modified version of android with that company's own messaging app as default.
I'm an Android user and I sometimes get nagged by Google to turn RCS on when I'm trying to send or receive an SMS / txt message.
I always say "NO!"
Why would I want to use RCS?
If I want to send a "rich" content message, I use Signal*, or sometimes email.
When I just want to send a basic text message, I use SMS.
When my doctor wants to remind me about an appointment, they use SMS; when my financial services providers want me to authorise a transaction, they all use SMS; and so on. Absolutely none of these interactions would be improved by making them "rich".
Also, I suspect that RCS would use my "data" allowance rather than the unlimited SMS messages included in my monthly account fee.
So, I ask again: Why would anyone want to use RCS?
* I used to use WhatsApp, but when that got integrated into the Metaverse, I stopped, and persuaded all my family & close friends to do the same