Telegram gives you a fairly high level of anonymity. But only if you yourself are ready to follow the rules:
- use two-factor authentication
- use a proxy (you can in the application itself or separately)
- use the "secret chat" function - in a regular chat in TG you are not protected at all
Not really. There are no completely secure messengers. For telegram, in order to get the maximum level of protection, it is necessary to remove QR codes from each other at a personal meeting. But! Account confirmation goes via SMS. Which in turn goes through the ssl protocol. And it can be completely intercepted by the special services. That is, the SMS can not only be duplicated to a third-party device, but can also be completely intercepted. This is how the telegrams of two opposition politicians were hacked, there was a story.