leo although your question is not addressed at me, I'd like to answer because I sympathize with Sbpr's post.
I do not like Telegram from the security and privacy perspective. It might be the most useful, beautiful and feature complete messenger out there, but not having encrypted messages by default (and only for 1:1 conversations via very hidden secret messages functionality) destroys all usability for me. I can't trust a "private" family group chat that is out there for everyone to read, no matter what company is behind it. WhatsApp, Facebook Messenger etc., despite all their flaws, offer better security and privacy on a baseline level I'm not willing to compromise.
But again: Design, features and usability have been top notch, so it might be suitable for many use cases where privacy and security doesn't matter (e.g. when registered with a non KYC phone number that isn't connected to any crucial accounts like banking).