I'm just thankful that mobile phone networks haven't switched to a "free with ads interspersed into your texts" model yet.
(Of course there are still ads in my texts, but at least those are officially spam rather than network endorsed.)
Market timing is hard.
It was an X.400-based nightmare, and never took off.
I know some very privacy-focused person (a friend of mine) who will stop being willing to be in contact with you (or being your friend) if you use an email address at one of these big spying email providers to write him an email.
So, it is just a matter of being consequential.
Literally in a span of months SMS usage went the way of the dinosaur.