Also, Telegram is not federated. It is just another vendor lock-in.

https://github.com/telegramdesktop/tdesktop/issues/6841

https://github.com/telegramdesktop/tdesktop/issues/16068

Contrast that to email. Even if gmail.com bans you or shuts down, you can still use a different email vendor or self-host. (You lose your old email address if you don't own a domain, but you can still communicate with others.) The only good IM that has this characteristic seems Matrix.