MythTV has movie/TV and music libraries, so it’s not too different than the other two. Also, you can use a tv tuner like TVheadend with jellyfin.
I used MythTV for years and eventually switched to Kodi to get more modern UIs. I eventually separated the server part with jellyfin to get more flexibility, keeping Kodi on little raspberry pi boxes as clients
Probably referring to Microsoft. That’s the one of the two with all the cloud experience