I have moved from Plex to Emby and finally to Jellyfin to run the Raspberry Pi media server in my camping van. The problem with Plex and Emby (other than their business model of wanting to collect a monthly fee for allowing you to watch yourown media) was that they required the server to phone home before they would work. This isn't possible if you are camping and don't have a cell/wifi signal.
And Jellyfin has worked well. The server and clients aren't as slick as Plex but they work just fine and give me a lot more flexiblity in moving media from my home server to the van since the way they store the media metainfo is the same on the Mac OS and the RPi OS.
If you're looking for a slick cross-platform Jellyfin client in the Apple ecosphere, try Infuse. It's quite polished, and even available for tvOS- my personal motivation for using it.
And Jellyfin has worked well. The server and clients aren't as slick as Plex but they work just fine and give me a lot more flexiblity in moving media from my home server to the van since the way they store the media metainfo is the same on the Mac OS and the RPi OS.