Just curious - I remember some debate here about Telegram bug bounty from a while ago, other than that haven't seen any good/bad press about it. Why is it bad counter-example?
It's a client that explicitly about security and openness, so a lot of things are going to be "self-evidently" supported. The objective is to make a good client
The objective of clients like LINE and WhatsApp are to make good chat for the masses. This can come at various technical costs, because that's not their objective, whereas Telegram is , at its core, about technology.