NucubeMusic first
“I use Plex or Jellyfin for the household, and I want a player that is only about music.”
A player whose whole job is music
Nucube is built for albums, artists, and the collection you own. It does not manage movies, TV, photos, or household users.
Stay with Plex or Jellyfin if one household media system is the point
Plex and Jellyfin are full media systems — movies, TV, photos, users, and remote access. Plexamp is a dedicated listening app on top of a Plex server, with a native desktop app for macOS, Windows, and Linux, and an offline mode. The Plexamp app is free; Plex Pass unlocks extras such as sonic mixes and downloads. Jellyfin’s main app treats music as one library among many; music-first clients such as Finamp exist for that front. Try Nucube if music is the whole job, and a player with no media server is what you want.