Selfhosted

Lifetime Pass holder here. Used to run Jellyfin alongside Plex. Had crashing issues and had to shut Jellyfin down for quite a bit. Came back after a while and started Jellyfin from scratch. None of my users ever chose Jellyfin over Plex.

• The UI is slower (at least on Windows), clunkier, and uglier. Hopefully this gets fixed in the upcoming big update they have planned for the desktop client. Their Roku app is actually on par with Plex's though.
• The admin dashboard is confusing and in my opinion awful.
• Downloaded content is not viewable within the app on Android. This is the complaint I've heard the most from my user who made a significant effort to switch. Ironically, after the New Experience update this became less of an issue since Plex ruined downloads.
• Plexamp's UI, radios, and sonic similarity feature were, last I checked, unmatched by a long-shot. I use my music library heavily. If I make the switch fully away from Plex, I'll probably opt for something more specialized like Navidrome.
• Manually setting the edition of a movie is so much easier on Plex, and for someone who likes to have multiple editions, it's less confusing for the user to see each edition individually labelled in the library than selecting the movie and being expected to know which file name they should pick. Not every file is named to Jellyfin's standards because that would make them harder to add to my torrent client, and some don't have their editions in the file name at all and I just have them hand-labelled in Plex based on run time.
• I'm still trying to setup my DVR in Jellyfin and can't get it to work. Plex works fine, Jellyfin just won't. It's a moot point at the moment, but once I do get it to work, unless things have changed over the years, the channel guide is a whole other set of challenges.

I'm willing to deal with this personally simply because Plex creates just as much, if not more of a headache for me as an administrator and the bloat is ridiculous, but not a single one of my users has switched, and I don't blame them. They don't have to deal with the administrative difficulties, so there's no benefit to them except being able to download files to their system instead of just in the app, which none of them care about. If nobody is going to use it, my focus ends up being on Plex anyway. I have been pushing Jellyfin for a year and a half. None of my friends or family want to use it unless Plex borks something, and even then they want Plex back.

Jellyfin just isn't on par with Plex, no matter how much I wish it was. It's death by a thousand cuts on both the user and administrative ends. It would be one thing if I were a free user or actively paying for Plex, but as a Lifetime Pass holder, I just can't justify it yet.