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/
Because there’s not a single good app for XMPP and nobody uses it.
Their bleeding edge app is Conversations which costs money (already unviable), and the app looks like it’s designed in 2012.