[TMWNN]

>It really always baffled me why Americans were using text messaging for so long

Because our mobile plans gave us gigantic buckets (thousands of SMS messages per month, then unlimited) before most other countries. It was the lack of such that drove the growth of WhatsApp and similar systems elsewhere.

>(and complaining about lack of encryption and so on)

Yeah, no one does that, any more than people complain about the lack of encrypted email.

(Yes, yes, it's possible to do both. My point is that most people don't bother in the first place.)