In my German circles, that spot has been covered by whatsapp for a long while now. It never has been instagram or anything else really. For me it went from studivz (long defunct German "facebook" for university students, didn't last long), via facebook (for a short while, and due to lack of alternatives) straight to whatsapp, and has stayed there ever since, with the exception of some photography interested people sharing larger sets of photos on flickr at times, and some dating/sexting happening on snap (but most of that still was/is on whatsapp). Instagram was always understood as a place where you go if you want to see celebs, influencers and the "wannabes".

Granted, I am a bit older, a millennial (as much as it hurts me to admit) and an older one at that, but I regularly take the tram in my city at times when all the teenagers are going to school or coming from school, and you can see a damn lot of whatsapp on all those phone screens, a lot of tiktok, and a good amount of discord.