Which ones? I have friends (young and old) all over Europe and everyone uses WhatsApp. Everywhere I've been in Europe defaults to WhatsApp, even for business communication.

Like, it's n=1, but still, my experience is quite broad.

EU: I'm trying to get everyone i know onto signal. Hard fight. I tried whatsapp for a month and it was so facebooky (that I also got rid of yeeaaars ago, after trying for a month) that I deleted it. Whatsapp is very common, though and I am gradually being pushed out of various communications (my doctor, for example, pharmacies). At least I don't have to bugger about with Teams which is the requirement for my kids' schools. Amicable divorce, but I don't have that on my phone, unlike my ex (who hates it).

In Denmark hardly anyone uses WhatsApp by default. No business I’ve seen uses it. Android is common.

I’m currently in Indonesia however, and it’s universal both privately and corporately.

At least in my experience most of the nordics is mostly iPhones and WhatsApp is somewhat rare.