They do care about SMS fees, especially across international borders.
They do care about sending group texts between Android and iOS and not having things go slowly haywire as messages don’t come across.
They do care about sending messages over wifi if they’re somewhere without a cell signal. (OK, bit of a Canadian thing, but the cottage has wifi and no cell signal.)
That you have to explain why you might be without cell signal shows that you are blessed up there. Today I talked with someone a few miles outside of Frankfurt (Germany) - huge financial hub - and the line broke down almost 3 times due to bad signal...
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^ That's and ultra low res photo sharing what you get when you group SMS/MMS with folks in the Apple ecosystem. You don't get it in WhatsApp, etc.