That‘s just a tiny reason of why most people moved away from SMS here. The biggest reason is the fact that SMS is a piece of **** technology with an abomination brother called MMS. People jumped on the WhatsApp bandwagon right away cause it was something new and offered more than SMS did. WhatsApp sadly had the first mover advantage so iMessage had not an ounce of chance when it was introduced with iOS 5. That and the fact that iMessage is Apple only and Apple has no real market power outside of the US.That’s because their carriers have price-gouged them for SMS messages and they’ve had to outsource their message infrastructure to an app that Facebook provides “free” (aka in exchange for an all you can eat buffet of data).
Fortunately, US carriers never quite got around to making SMS super expensive so we don’t have to do that.
Even if carriers suddenly decided to wave all fees for SMS, no one in their right mind would revert to such an ancient protocol that isn‘t even encrypted in transit.