SingleFile is very good for saving full pages with all their content as, well, a single html file.
That’s not very typical, I’d like to make that point.
Telegram doesn’t have this to such an extent. If someone has your number in their contacts and you join Telegram they see you whether you want it or not. Signal (now) hides that too.
As I see it, they are close to parity on the video/shows side, but the music thing on Jellyfin is severely lacking for me. PlexAmp and all the special mix and radio features are where it’s at for me, and so far I don’t know of an open alternative to that.