Well, I can't say Signal vs. Telegram, because despite I do have Signal, I use it extremely rare (well, almost never, - there are not so many contacts in there)

Well, I can't say Signal vs. Telegram, because despite I do have Signal, I use it extremely rare (well, almost never, - there are not so many contacts in there), but comparing WhatsApp vs Telegram is easy - TG is infinitely more convenient and well-thought. Just like a good old shoe, that fits you perfectly. However, I'm quite concerned about its security (though I have no facts or evidences) and that why I'm looking into Signal...