But they have stickers and a gif bot, so normies are going to use that over Signal. And no issues with synchronization between devices (since it's just plaintext xD xD). Seriously.. "secure messaging app" doesn't even have secret chats in the official desktop client.
I use Telegram not for bots and stickers but for the fact that it has a quality native Mac client. Signal's desktop client, with its reliance on Chrome/Electron and need to sync with your phone, is half baked and annoying by comparison. I sit in front of computers for over 8 hours every day, so they serve as my digital messaging center far more than my phone does. That calls for a chat app that doesn't make the desktop an afterthought.
not sure what you mean, I use the official app on OSX and it has the secret chat option. click on a contact, it shows you all the infos including "start secret chat"
Anyone could claim absolutely anything, and the bigger the player the more likely it would be without any negative consequences (and with positive ones until the discovery - and sometimes even after), even if it's discovered to be an outright, blatant lie. Not like Telegram is unique or exceptional in this regard.