Earlier quoted context omitted.
If Telegram relies on SMS for its authentication system, wouldn't the SMS network be part of its infrastructure, if indirectly?
Facebook relies on SMS. Whatsapp relies on SMS. VK relies on SMS. Viber relis on SMS. Are we going to say that all of those have been breached too?
Applications should not rely on SMS for authentication or login, or on the phone number for identity.
(Disclaimer: Threema dev)