Jellyfin doesnt handle music quite as well as Navidrome does. Jellyfin is awesome for watchable media but it lacks a little on music. Navidrome handles artist metadata better. For clients, 100% Feishin on desktop, its just about perfect. On mobile, Castafiore or Resonus I think are two of the best. Finamp is great for a Jellyfin client on mobile but still it depends on the Jellyfin server which again doesnt handle metadata as well.

Audiobookshelf for audiobooks and Navidrome for music.

audiobookshelf for audiobooks specifically, with Lissen as the android client.

For music, Navidrome with Tempus as android client and Feishin as desktop client, all scrobbling to ListenBrainz.

I started using Navidrom as suggested by someone in the group. I do not have audio books but it has a spot for them. If you want to get all fancy like you can use the MusicBrainz Picard for tagging stuff differently (or something like that I am really feeling the glue and sealant they used to put down the laminate in my place right now) but AudioMuse-AI does something to (again really feeling it).

I dont use Jellyfin, but I heard of some of the things it did and jellyfin sounded like a step above due to its dedicated music app and similar songs for playlists.

I use Navidrome as the server and Symfonium for the mobile app. It is by far the best option I have ever used in the 20 years of setting up a personal server. I used Subsonic before this but it was abandoned years ago and Navidrome is a fork of it. The amount of continuous effort put in and new features that still get released is fantastic. Im always excited when i see a new version drop.