I've used it for months and I still couldn't tell you exactly how it works. Open efforts like Mastodon desperately need simple infographics to explain the service to newcomers or you'll end up with a bunch of ex-twatter users signing up, using it for 5 minutes, being annoyed that it's not nearly as simple as twatter and then idling their accounts while they switch to something else. See also: matrix, which has some uptake by the open source technical crowd but nowhere near the general adoption of telegram.