Absolutely _not_ the case here (France), the overwhelming default is SMS (and now RCS). Sure people use WhatsApp but also Telegram just as much these days, but in both cases it's _not the default_.

Maybe because it's been, I don't know, one to two decades that SMS have been unlimited in even the most basic plans.

Also RCS Just Works here, I've seen my non-Apple contacts move to RCS over time as they got OS or phone upgrades.

I'd blame NA carriers, which, from afar, seem to have a habit of screwing up in so many ways.