Yeah I recently learned from a Candadian friend that people in the US and Canada still text a lot? Outside of the US & Canada my estimate would be that 99% of people has switched to WeChat, Whatsapp and FB Messenger.
The only texts I ever recieve nowadays are automated (2FA etc...). Even though unlimited texts come with every SIM.
I am a rarity here in the U.K. as I still text, having got fed up of constantly switching IM apps. I mean, I remember when MSN Messenger was all the rage. Then Yahoo, ICQ, GTalk, Hangouts, various Jabber protocols, FaceAche, errr I mean FaceTime and Messenger, WhatsApp etc etc ad nauseum, Skype
SMS has remained the great constant throughout all these games. Turns out people don't get in touch if you don't use WhatsApp but shows how much they care eh!
If your GSM network is anything like Greece's (and I don't doubt it is, grey market devices from Spain sold here work without issue), Android automatically sets up the network settings for MMS and wireless networking. You don't have to do anything.
The only texts I ever recieve nowadays are automated (2FA etc...). Even though unlimited texts come with every SIM.