I have both and run them side by side through Docker in UNRaid, but Jellyfin hardly ever gets used unless there is a problem with Plex and I don’t feel like fixing it immediately. I’ve had the Plex lifetime pass for forever.

I have young kids and really like Plex’s system for moderating content for their accounts. I’ve never explored this on Jellyfin though. As a person with crappy laptop speakers, subtitles are important to me. Plex does subtitles better than Jellyfin in my experience.