I recently set up Sonarr and Radarr on my home server and I'm loving it.
However, I don't get why you would ever use Lidarr. Why would you ever download music using torrents? You can use tools like spotdl and yt-dlp to download songs from YouTube music and Spotify, it's faster and more reliable; I have had some issues finding torrents of music from less-known artists.
To me it seems like it would be much better to have a tool like Lidarr or have support in Jellyseerr to download music from common streaming services.
Because some music is not available on streaming platforms. Occasionally artists and labels decide to split their ways, and suddenly their older albums are gone. Over the years I started losing notable chunks of music I like from my playlists.