I think what you want is either plex or Jellyfin which will give you a nice UI to browse your already downloaded files.
Now how do you browse new releases and figure out what you want to download? I just setup https://overseerr.dev/ to go along with sonarr, radarr, prowlarr, nzbget, transmission... it's a lot of different services but they all work well together. Now to look for new movies, I or my family goes to Overseerr to request downloads, then plex to watch.
I had a coworker come to me with an "issue" he learned about. It was wrong and it wasn't really an issue and the it came out that he got it from ChatGPT and didn't really know what he was talking about, nor could he cite an actual source.
I've also played around with it and it's given me straight up wrong answers. I don't think it's really worth it.
I think what you want is either plex or Jellyfin which will give you a nice UI to browse your already downloaded files.
Now how do you browse new releases and figure out what you want to download? I just setup https://overseerr.dev/ to go along with sonarr, radarr, prowlarr, nzbget, transmission... it's a lot of different services but they all work well together. Now to look for new movies, I or my family goes to Overseerr to request downloads, then plex to watch.