[tgsovlerkhgsel]

It seems to be the only currently existing open, e2e encrypted, chat application that reasonably supports both multi-device and large group chats. Essentially Slack or Discord without the centralization.

The nearest competitor is Signal but that's neither really open (it's source-available, maybe technically open source but it's clear that you aren't supposed to try to interop with the official network with non-offical clients) nor does it really seem to be made to support large group chats and a desktop-first experience.