Many in the crypto and privacy community mistakenly trust Telegram because it’s “end to end encrypted”, but there are huge issues including not hiding the metadata, censorship, centralization, and phone numbers.
Send this video to your friend that asks why you won’t join:
https://video.simplifiedprivacy.com/why-telegram-sucks/
The only thing Telegram has going for itself is that it’s Non-Meta and Non-Western.
Anyone who has a closer look at Telegram’s reputation knows that their privacy claims are dubious. If you want end to end encryption, even WhatsApp is better. But these things depend on your individual threat model.
Telegram can be E2E, no reason to switch to Meta’s app for it