I switched from Plex to Jellyfin several years ago and haven’t really looked back. Overall I just didn’t like the direction plex kept going (pushing shit streaming services, central auth, paywalling features), and dropped it even though I grabbed a lifetime plex pass back in the day. The only thing I miss about plex was the ease of developing a custom plugin for it since you could pretty much just drop python scripts in there and have it work, though their documentation for plugin development was terrible (and I think removed from their site entirely).