Telegram isn't as private as iMessage, but that doesn't mean it's not as secure. Security-wise, exploiting iMessage is easier than exploiting telegram, since iMessages has some special privileged access. Security doesn't mean privacy.

The issue with parsing images in a process was fixed awhile back. If you are really paranoid, you can put your iPhone in “lockdown mode”.

https://support.apple.com/en-us/105120

You rebutted something GP didn't write.

This is true (one is talking about zero-click zero days, the other is talking about “privacy,” not sure if they mean privacy against Facebook or privacy against other users of their device).

But the comment that kicked off the thread was the one about privacy.