WhatsApp is the defacto messaging over data globally. If you live anywhere outside the Murican bubble, SMSs are not used for anything and iMessage isn't even a thing people with iCrap devices care about. Everyone, on every platform, uses WhatsApp. Governmental services, private companies, and all the people use WhatsApp.
The only text messages SMS I get nowadays are from Americans that don't understand anything else and American businesses that use them for 2FA which is super insecure and equally stupid.