I use Plex for (1) home library, (2) Live TV (HDHomerun), and (3) music (PlexAmp).
(1) Jellyfin is just as capable for home streaming of my home library.
(2) It would take approximately 15 seconds to show my live TV when I switch stations. Plex is almost instant and Plex has ad supported channels similar to a PlutoTV, et. al. I watch Scripps News and NBC Now along side my locals.
(3) There simply is no app as good as PlexAmp.
Finally, setting up Plex for outside access was dead simple, Jellyfin takes some effort.
I haven’t used those apps in a long time, so my experience is pretty dated. PlexAmp is very very good though.