I tried Jellyfin years ago, it is in my test for later todo since then, it was pretty vanilla compared to my Plex Media Server (for instance I couldn't get to work the transcoder to use quick sync to lower the CPU load if needed, meanwhile Plex worked fine with the Docker container even).
With that said, I stopped using Plex daily in order to give some use to my Real Debrid account (so Stremio and Kodi are the next logical alternatives for me) and because I only have a two bay NAS with 10 TB in total, and I like to hoard so I struggle every time I need to delete something, since I knew about Riven/Zurg/Rclone/DMM combo I have returned using Plex without worrying each day about my drives, keeping it updated and enjoying the thinkering process of this new experience, also sharing the love with a couple of friends, I see no need to try Jellyfin, even after that many years.