You can't enable 1:1 secret chat from your desktop client. The secret chat doesn't appear on desktop when you enable it on your phone. So you're forced to drop end-to-end encryption if you want interoperability between phone and desktop clients. You can't enable secret chats for group chats on any client. The company isn't working to make secret chats actually usable.
>I guess you are from Ukraine?
Nope.
>Definitely not Signal, slow and unfriendly
The thing is, friendly apps are apps that respect your human right to privacy. There's a term for applications that appear to do something useful while doing something against the user's interests without them knowing: A Trojan Horse. Which is a malware classification.
When you view it through that lens, Telegram is the unfriendliest app out there outside completely unencrypted messengers like Palringo (at least used to be the case), where anyone can read your message from the cable with WireShark.