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.
Session was at first a fork of Signal without usernames.
Now by design it uses their own custom tor-like service (instead of just… using tor) and does not support forward secrecy or deniable authentication, so anyone who collects the messages in transit can either find a vulnerability in the encryption scheme, or spend enough GPU resources to crack it, and they have confirmation of who sent and received the message and what the contents of the message are. And is headquartered in Australia, which is 5EYES and much more against encryption than the US. Oh, and the server is closed-source.
Regarding Australia’s 2018 bill…
Regarding the ‘vulnerability or cracking them later’ bit…
From Session’s own FAQ:
I wouldn’t touch it with a 12ft ladder.