I remember early iPhone users complaining here in the EU that their iPhone unpredictably would sent iMessages either for free over wifi or for 50ct/message over sms/text (us EU citizens avoid sms/texting like the plague, allthough unlimited plans are now more commonplace, it's just too late). I recently set Signal to deal with my sms/text messages. Boy was that an expensive mistake when I accidentally texted my friend in Curacao instead of sending a normal Signal message.
You need to specify where in the EU, because it doesn't mirror my experience in France for instance. Data used to be very expensive while there were no shortages of plans with near-unlimited texts. It also isn't the case in many other countries in the world in my experience. AFAIK the advantage of WhatsApp over plain texts isn't that it's cheaper per-se, it's that it works over wi-fi which means that as long as you find a hotspot anywhere in the world you can use it. No need to worry about roaming fees, no need to worry about how many texts or MB of data are in your plan.
Americans mostly talk to other Americans, who also have unlimited texting plans. French people are probably talking to people who live in Belgium, Germany, the UK, Spain, etc. who will all encourage them to use WhatsApp.
International texting is expensive though, while it's free in Whatsapp. Which is why it took off among various diasporas.
In Poland at least, SMS costs 0 in almost all plans.
As for WhatsApp, I try to keep people away from it and show them Signal, as I do not trust Facebook with any of my data.
Imagine if every state in the US was a different country. That's basically Europe. Say you got charged roaming fees every time you traveled from New York to Connecticut. This was true in Europe until they passed regulation that mandated compatibility.
Wi-fi had no roaming upcharge. Hence why texting that works over wi-fi became the default.
And it hadn't exactly "not penetrated" NA, there are probably tens of millions of users. But it's definitely not "the default mode of communication" as in Brazil or India (+ lots of other countries).
In the university i’m affiliated with and the companies i’ve worked with, only IT people use Telegram. Everyone else still defaults to whatsapp.
Everyone of my closest friends use Telegram. I share a number of groups with 300-400 people (family, extended family, organizations I belong to/contribute to etc).
Last time I got a message on WhatsApp was from an ex-colleague 2 years ago or something. With my new phone I didn't even bother installing it.
That said: none of my current colleagues (in tech) uses Telegram or WhatsApp for that matter.
