I’m from Mexico, and the most used chat application is WhatsApp. It’s used for EVERYTHING. I use Telegram only for contacting my family members (both my parents and my brother). They also use it only for this family chat. All my (and their) contacts use WhatsApp instead.
Now with the news that Telegram will collaborate with Twitter, I feel that I should delete it. Not that Zuck is any better than Musk, but still…
Also I don’t think it’s worth the effort to teach my parents yet another messaging app, like signal.
Threema. And don’t forget, real privacy and security, with centralized services, is never free. The app is tested by third party and is open source. And, you don’t have to share your phone number, unlike with Signal.
You no longer have to share your phone number in signal. They added a unique user identifier a while ago that you can share to add new contacts. This is not permanent by the way, you can change this user identifier anytime.