Finally jumped ship to a Jellyfin based home server and couldn't be happier. The ui is surprisingly good and polished (especially for the users who don't have to manage the library), video quality is amazing (with bd source files, who would have thought, but even DVD is often better than what modern streaming provides), and I can cache the movies on my phone when needed. It works in ANY browser under ANY os, doesn't…
I find the free version of plex - once I config out all their own streaming junk - is perfectly good.. (and it runs acceptably on my ancient synology) Are there any compelling reasons for me to look in to jellyfin?
It just looks to me that Plex (as a company) isn't really as reliable for self-hosting in the long run. So even though Plex has a better client support (for example, on xbox and playstation), I decided against it in favor of something that only I am in control of.
Initially intended to buy a license for Emby, but it doesn't support hardware transcoding on Apple Silicon yet, so Jellyfin it is then.
If you are happy with Plex, there's no reason to switch, IMO. If something goes wrong, it likely won't take you long to connect an alternative to the same media library