I recently switched from Plex to Jellyfin. It's far more stable and hardware decoding works out of the box.
The server is a joke, most of the “functionality” is half/baked or outright broken.
The “native” clients are laughably bad. Most of them cannot pass-through audio to receivers reliably.
I really want Jellyfin to succeed, but it’s an incredibly long way from replacing the long-time dumpster fire that is Plex.
(Context: I was a Plex user and self-hoster for about 7 years, and switched to self-hosted Jellyfin about 2 years ago.)
If you have a device that can run it, I find that Kodi is the best frontend for JF. It has a lot of extra features that the normal client doesn't.