Many Telegram groups are only Play Store banned or banned access is restricted based on the user's phone number. This is why you must install the APK from their website directly instead of using an App Store version.
This have nothing to do with Apple. One of largest anti-war public channels in Russia by relatives of mobilized people was marked as "FAKE" for a very long time by Durov's personal decision.
Durov serves kremlin as much as any other company that operates in Russia.
It is ridiculous that Apple decides what Telegram users can or cannot see, especially banning harmless things like nudity but allowing cruel things like war videos or propaganda.
WhatsApp isn't E2EE by default either, since default flow pushes you to backup your key to Google Drive.
Signal isn't E2EE, given the security blunder in which private images from your gallery were sent to random contacts (which indicates a scary state management situation in the apps, this isn't easy to do). E2EE implies that you purposely send content to specific people which is encrypted, not that your app sends potentially embarrassing or intimate pictures to your boss behind your back. That blunder is unforgivable.
Also Telegram banned or shadowbanned serveral protest channels / bots during elections and when war began.