It mostly comes down to personal preference honestly.

Jellyfin is open-source and more focused on your own selfhosted media. I, too, bought a Plex pass years ago and have enjoyed Plex but they've been adding a bunch of crap to their interface.

I'm big on free open-source software but I won't be biased and say that Jellyfin has some rough edges, but it works well enough for me to watch movies with my wife. Plex is a bit smoother and more production-ready for those power users that host Plex for several others.

I'd encourage you to try it out if for nothing more than exposing yourself to alternatives.

The main reason I use jellyfin over plex is just because they only host my media, nothing else. None of the plex pass bs cluttering it up

Also a Plex lifetime user. I tried jellyfin not too long ago to see what the fuss was all about. I had heard that they handled her tonemapping better.

The interface is different but more or less just as good as Plex. It's definitely more for the person that likes to dive in the details of the config of their server. For example, you need to setup your own domain for external users to connect to. It's not done automatically like on Plex.

The focus on your content vs the "free" content Plex shoves in our face is nice I must admit.

Just a question of preference. In the end I stuck it out with Plex... For now.

Plex is better overall currently imo having tried both recently. It's just simply more mature software where things just work and it has a ton more features.

Jellyfin is pretty awesome though in its own right and heading in a great direction.

I too would like to know...

Same situation