You also have to take into account that SMS is 5-10 times more expensive almost everywhere outside the US. Unless you have a flat-rate plan, a single 140 character messages is about 10 cents where I live. And even if you have a flat-rate plan for domestic messages, it's 1-2 USD (per message!) when sent to friends and family abroad. I don't use SMS because it's just being ridiculously over-priced. I want my device to use data to send data, regardless of what kind it is.
It's (sms/texting) free (http://mobile.free.fr/) and unlimited on a 2 euros monthly phone subscription with 2 hours of voice communication in France. That makes it the cheapest way to communicate at all, here. Cheaper than voice and much cheaper than internet data. Even the absolute poorest of the country can use texting. It's more accessible than DATA driven apps and can run on dumb phones.
People use Whatsapp primarily, or facebook messenger, or (in my bubble anyway, not so widespread) Telegram. These products have the network effect already established, and no one is likely to go back to crappy SMS, even if it is dressed up.
No, noone uses it because it doesn't use data. I walk into a supermarket and lose signal so I can't SMS anymore. I can use the wifi to send messages even without signal.
Yes, I know there are SMS over Wifi apps, but they're proprietary and usually require signal to enable.
Isn't that recursive thinking? No one uses SMS because it's primitive and limited compared to regular messengers.
> I wouldn't want to use a mobile only protocol
I'm curious, but could RCS be interchangeably used both through provider and through a host such as Google? Could Google not host their own RCS backend?