Better is subjective.

Simpler in a more streamlined sense, yes. Plex is more hands-off, and is doing a lot behind the scenes to automatically configure itself to your hardware for the best transcoding experience and such.

Jellyfin needs a little more work but can get there, it just needs to be shown the hardware and be configured correctly, but I find Jellyfin to be simpler and less cluttered overall when properly finished, with less strings attached to a parent company.