That might have been the original reason, but right now most plans come with unlimited text messages in my country and that didn’t entice anyone to switch back.

That might have been the original reason, but right now most plans come with unlimited text messages in my country and that didn’t entice anyone to switch back. iMessage is great when all your contacts own an Apple device, but if not, your using ancient text messages with very limited functionality compared to the cross-platform messaging app that everyone is already using.