we dont use jellyfin for music.. https://www.navidrome.org/

edit: i just realized i am in the jellyfin community amd not selfhosted but my answer doesnt change. there isnt one app to do everything well.

Works perfectly well for me with a Jellyfin server and Symfonium app on Android. Playlists sync fine and you can edit them on the phone.

I use JF for music, I have a big library (16k songs, some are sorted by album (one folder by album with songs inside) and some are sorted by genre (one folder by genre), all folder are treated as album, which is fine with me.

Then, I often play songs at random, and sometimes I add some songs to playlists ive created. I also use finamp

However, Jellyfin has a BIG performance issue with music... This will be mostly fixed in the next big release, but in the meantime, loading and playing songs takes a long time... I go around this with Finamp.offline mode and having downloaded songs on my phones beforehand.

https://github.com/jyourstone/jellyfin-smartlists-plugin

https://neptunehub.github.io/AudioMuse-AI/

Smartlists is great for rule-based playlists.

AudioMuse-AI analyses the sound, for something a bit more dynamic.

There was also a BetterLists plugin but I dont think its actively maintained.