Why do some people prefer using Telegram for chats and calls? (Especially in the gay community)

Hi, I’m from Japan and I’ve noticed that many foreign guys — especially in the gay community — seem to prefer using Telegram for chatting and calling.

I’m genuinely curious: Is this mainly for privacy and security reasons, like preventing data leaks? Or is it sometimes also used for more shady or illegal activities?

I don’t mean any offense — I’m just trying to understand the cultural or practical reasons behind it. Thank you for any insights you can share!