Plex can "hide" (not really) your own server because you can direct your users on Plex.tv (they can login there, etc. without ever typing your IP address).
But Plex can also use an internal reverse proxy that lets you see your content from outside even without port forwarding. However, quality and speed will be decreased.
I think Jellyfin should work to ease the process of setting up your server as much as they can, but unless they start managing a SaaS like Plex does, they'll never be able to offer the same simplicity for the end user.