Originally Posted by
ElevatorEnthusiast
Agreed, having to support every communication method in use by every country would be untenable. Major airlines have large customer bases outside of their regions of origin, and some regions have very small user bases of apps that are largely used in other regions. For example, I know basically zero people in the US who use WhatsApp unless they have family in another country where WhatsApp is popular. The same can be said of other messaging apps. Voice services are ubiquitous, and significant infrastructure has been developed over the years to support temporary voice connectivity for tourists.
The only country I have travelled to in recent years that doesn't seem to use WhatsApp is the USA. And, in the USA, I've never seen any infrastructure to support temporary voice connectivity for tourists. That's why I have to have a US SIM as otherwise it's impossible there. I don't find that elsewhere.