Earlier quoted context omitted.
>I can easily guess that assholes in secret service would probably like very much to use that to blackmail him to add backdoors to telegram Do you unironically believe it's not already backdoored for Russian government?
Durov was notorious in Russia for refusing to cooperate with FSB (successor to KGB), too. I remember when FSB asked him to give access to protester communications on VK (in 2011 during mass protests), he mockingly responded with a picture of a dog with its tongue out (showing your tongue means "I won't give it to ya" in Russian culture). That's why he left Russia, because he felt he'd get arrested soon. Quite ironic…
And how exactly do you think it got unbanned?
Their "encryption" used to use an in-house algorithm (in house algorithms almost always are vastly inferior to standard ones) and even today encryption stores the keys on their servers (in Russia...) and E2EE has to be enabled per-conversation by hand.