There are a lot of apps that don’t encrypt at all (e.g. Google chat, discord, etc)
There are apps that encrypt but they are subject to jurisdictions that can or may in the future force backdoors (e.g., Chinese apps, possibly telegram, possibly US apps in the future)
There are apps that encrypt, are in countries that are privacy focused but are not for free (e.g., threema)
This contributes to a fragmentation that makes WhatsApp the app that-you-must-have
Sure it is supposedly encrypted but I would not bet my money that is without back doors
That, I guess, it’s the whole point. Stopping being tracked 🙂