That's not because of its policies, it's just that Telegram is very popular in Eastern Europe/post-USSR land, network effects and such.
Re:New Upcoming Telegram Premium Features
by generationP on Tuesday June 07, 2022 @01:35PM
(#31657639)
Twitter and Youtube are a censorship minefield as it comes to war footage. Russian trolls have been known to mass-report pro-Ukrainian accounts for posting "NSFL" material (and much of the interesting material from the front is NSFL). If you are famous and know the right people in the West, you can get unbanned through your connections, but this is a lot harder for the local sources.
The idea that Telegram is in any way safer than the other platforms, I really don't see much to speak for it.
It's similar to ProtonMail: you get it as a backup in case you get locked out of your googlemail; you don't get it to conspire.