And Signal still insists on your phone number for registration, and then shares it to any of your contacts (unlike Telegram who gives you the option to hide it). Signal is US based whilst many others are not. I’m not saying Telegram is better (unless you;'ve activated secret chats) but the better ones like Threema, Jami, XMPP, Matrix, and similar are just not the one’s we’re going to see adopted mainstream. Matrix is complicated for average users.

It’s pretty well much a race between WhatsApp, Signal and Telegram as far as ‘popularity’ goes.