Sure, fuck WhatsApp, but Telegram isn't even end-to-end encrypted most of the time. Their group chats never are, and their "secret chat" encryption for non-group chats must be explicitly enabled and hardly ever is because it disables some features. And when it is encrypted, it's with some dubious nonstandard cryptography.
It's also pseudo open source; they do publish source code once in a while but it never corresponds to the binaries that nearly everyone actually uses.
And the audacity to talk about metadata when Telegram accounts still require a phone number today (as they did five years ago when this post was written) is just... 🤯
State-sponsored exploits against WhatsApp might be more common than against Telegram, or at least we hear about them more, but it's not because the app is more vulnerable: it's because governments don't need to compromise the endpoint to read your Telegram messages: they can just add a new device to your account with an SMS and see everything.
(╯° °）╯︵ ┻━┻
Anything claiming to prioritize privacy yet asking for your phone number (Telegram, WhatsApp, Signal, ...) is a farce.