alt Hacker NewsIn countries where SMS isn't as widespread as it is in the US, the use of WhatsApp is much more common.
I live in one of those countries, and I don't think I've ever had to use it to communicate with someone on another continent. I think most of its use is simply local, for your community or friend group.
The downside for me is basically the lack of appeal for a non-tech user (like my parents) to voluntarily want to stop using an app they've been using for, what, 10-12 years? It’s not that big of a deal; everyone uses Instagram or Facebook (maybe)... WhatsApp is definitely going to make the process difficult, too.
Whatsapp is more popular in the US than you'd think. Probably due to a large immigrant population. I'm in several groups that use the channels feature to organize things like soccer, game nights etc. Most people with family abroad use Whatsapp, and that's a huge portion of the US.