Jellyfin is my jam, it just works. Its administration interface is intuitive, pretty solid, personally I think the dashboard looks good aesthetically, and most importantly it’s open source so if anything is broken I can just fix it myself. If anyone is interested in feel free to check out Swiftfin (https://github.com/jellyfin/Swiftfin) a native iOS client
Here is the beta app for Apple TV: https://github.com/jellyfin/Swiftfin
It‘s a bit unstable for me, so I switched to the web app on my iPad and beam it with AirPlay to my Apple TV.
There is a first party Apple TV Client, but its still in development. They do have a public test flight for it:
I think a lot of the app's issues arise from not being a native app. There is work to develop a native iOS app[1] which looks really promising. Unfortunately that doesn't have an option for offline playback just yet but it is in the works.
I love Jellyfin, but its inability to Chromecast from iOS is a dealbreaker. I think they’re working on a whole new iOS app though that has a working chromecast button - https://github.com/jellyfin/Swiftfin