It was a many months transition, and it's finally done
Fun thing, you can actually make a backup of all* your messages, groups, contacts, etc. So before leaving you can have all of your data in case you need that one contact or something
The final red flag was as that allegedly Russian authorities were messing with people's deleted messages. Not for the first time there are news that they could read, modify, delete, see location, and etc. Screw it, this is unsafe, I'm out.
Also, these days telegram is really at the state of a pile of garbage, bloated, buggy, and shady messenger.
I don't know about "Russian authorities", but the fact remains that if you can login anywhere and see your messages, then your ~~public~~ private key is stored in the server.
Since Telegram requires authorization from an extant connection, I don't know if that means your public key isn't stored on the servers and it's being sent from the authorizing device, or if that device is merely authorizing the Telegram servers to transmit that key to the new device.
Since they have a full e2e chat feature (Private Chats), I'm going to assume the latter.
So anyone who can get those keys can gain access to your chats.
I still say Telegram is far superior to anything from Fuckbook/Meta, because it's not integrated into everying you do (even those of us who've never once been on Facebook, and yet have ghost profiles), not to mention the Facebook app integrated into Android on many vendor phones.
Even so, know Telegram for what it is - not ideal, just better than WhatsApp, and a step along the path to moving to more secure and privacy-respecting apps.l
Did you mean private key?
I automatically read it as private key, good catch