I’m European and I pretty much only use SMS with family members and such. It always works! But pretty much everyone in my extended family uses an iPhone which is annoying when I want to send or receive big media files. So it would be very nice if iOS started to support RCS messaging
I primarily use Discord with friends. I don’t think I have ever met one that uses signal or Telegram regularly. The only ones I know that use whatsapp are my parents. Old people mostly use Facebook messenger or maybe whatsapp I believe.