I have jellyfin with the radarr/sonarr/prowlarr combo going. I can “heart” things in jellyfin. But it’s recommendations are only things I already have downloaded. I see discovery in radarr, but no way to tell it if the movies I downloaded were good or bad. So I must be missing something.
I use Trakt for tv and movies and ListenBrainz for music. Both have plugins to allow them to integrate with Jellyfin.
Never used Trakt, but I’m a big fan of ListenBrainz. It’s a large part of why I felt able to cancel my Spotify subscription