Knowing someone's phone number doesn't automatically let you compromise their device. This is such a ridiculous argument.
>I would rather know that this app is not secure so I don’t share anything important, while keeping secure communication to other means.
This is nirvana fallacy. It's essentially saying "We should not talk about Telegram lying about its security, when in reality nothing is 100% secure". Yeah, nothing is, there's always an attack. That doesn't contribute anything of interest to the topic, it just tries to kill the criticism. And I'm saying this as someone who has worked on this exact topic for ten years: https://github.com/maqp/tfc