> Certainly in times past in the US receiving calls/texts could incur charges.

That's why I originally said it was weird to me as somebody outside the US.

It dated to mobile calls being expensive especially outside of a very bounded home area and being either a business expense or a relatively luxury thing. In that context, it didn't really make sense to hit a landline with a big charge for calling a mobile number--perhaps unwittingly. And that general thinking carried over to SMS.