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/
It’s not misinformation, but it’s also not free. You have to “get a fake number” of sorts from the Fragment blockchain.
I don’t know much about those specifics because I live in the US, and fragment doesn’t work here (due to conflicting views with the FEC). In theory, a VPN might let you do what you want even if you are in the US.
https://fragment.com/numbers