Anecdotal data point from Germany. SMS is still 9ct per message if you don't pay for a package with included text messages, MMS is around 39ct/300kb, and as far as I know there are no (and have never been at any price point) packages with included MMS messages.
It's not surprising >90% of people in Germany use WhatsApp (+ other messengers)
It's not surprising >90% of people in Germany use WhatsApp (+ other messengers)