The only large group of people who still primarily use SMS to communicate person-to-person is Android users in the USA.
Every other country has settled on either Telegram, WeChat, WhatsApp or FB Messenger, or other niche apps. These apps work on both iOS and Android and often also Windows. I haven't sent an SMS in probably 12 years. I don't know anyone who has.
It's only in the US that iMessage is so prevalent that Android users have to use SMS, the only other way of messaging iOS devices. And the US is quickly becoming a de-facto iOS only country. It already has more than 50% market share, even 80% among young people.
With the US going (almost) full iMessage and the rest of the world having already settled on another app there simply no point to supporting SMS.
My wife's boss communicates with all her employees by SMS (mass SMS - works like group communication, both ways).
AddEdit: Airlines send their notifications and links to boarding passes etc. via SMS. Dentist and doctor appointments, other public office appointments (e.g. my upcoming passport renewal), document notifications (from pension fund insurance companies for example), public warnings ("Toxic fire nearby - close your windows"), and more, are via SMS where I live.
So if I'm not traveling I stay with the cheapest data option for my occasionally otg stuff and on heavy travel months I choose larger packages, because I found myself using more often, for example as access point to notebook.
I also have an Kaufland (Telekom) Prepaid card, that said it would provide basic, very slow internet, for free so that text messages over chat works, bur I don't know if I got the wrong APN settings, it has problems in my second slot or it only works if you top it up regularly, but that internet and rest never really worked, even the account management over the website doesn't really work for me.