It is elsewhere now it's just in the past it used to be stupidly expensive to send SMS.
It's wjere text speak came from, I believe they used to actually charge by the character so if you wanted to tell somebody you'll "be at the train station in 15 minutes" that's quite a lot of characters, so that became "@ stn n 15" which is almost incomprehensible these days.
When WhatsApp became available everybody went over because suddenly you could communicate like humans, after the phone company's realized that the jig was up they lowered text prices but by that point everyone had gotten used to just using WhatsApp. Then Apple came along with iMessage and no one could see the point because it only worked on iPhones whereas WhatsApp work for everyone.