Phone numbers are NOT safe. I don't know why SMS MFA is even a thing, they're worse than passwords.
When you use phone numbers or SMS for security, you are putting the fate of your entire company's security on an underpaid customer service rep at Verizon.
At least since version 2.0 it seems it's using AES encryption: https://core.telegram.org/mtproto/description
Telegram on the other hand is better for issues like this, where large numbers of people need to communicate anonymously without prying eyes.
They're addressing the same issue for different markets. That's all it is.
- Multi Device
Seems to me that are some of the most useful things about modern chat.
Also, why not just use a chat app that is save by default. The whole concept of private chat is insane to me.