I suppose it aims to be private. According to their FAQ:
- No 3rd-party content, ads, analytics, or trackers
- Messages are forwarded, but may be stored on their servers in case of a failed delivery
- Servers are in the Netherlands with Greenhost, which claims to focus on privacy. A backup server is in Poland with UpCloud
- Messages can be encrypted (including attachments) with your own GPG/OpenPGP key if you enable the option
The author answers "what if I don't trust you?" by pointing out that you can host Addy on your own server. It is fully OSS and you don't need to use their cloud service.
I wouldn't put Telegram at the level. I would put it in "The Brainwashed." Its encryption is disabled by default. You need to manually enable it on each chat, and you can't enable it on group chats. The app gives a false sense of privacy. Telegram flaunts its end-to-end encryption, but it never mentions that it is disabled by default, and it refuses to enable the default. The final result is that people are not using the feature.
A cryptographer and professor wrote a good piece about Telegram's encryption, calling it "unusual" and the "non-standard authenticated encryption mode ever invented": Is Telegram really an encrypted messaging app?