Telegram changed in the last couple of years. You can choose between secret chats (e2e encrypted) and normal which are just user-server storage-user encrypted. End-to-end voice calls is also a feature. If you ask me between the Google / Facebook messaging apps (Whatsapp, Messenger, etc) and Telegram, today I'd say Telegram has an advantage because it has a good UI, works across devices and the desktop client works like a charm. For someone that wants to ditch the Google / Facebook environment and be sure their grandmother can use it, I don't see much better options.

It's not as faulty as it used to be, but I see the old times made a reputation for it.