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/
That article was written in Dec 2022. either something was lost in translation or Telegram ditched the idea.
As stated before, you cannot use telegram without a phone number, which is a threat to security, anonymity, and privacy.