I've been a Plex user for over a decade, I have a lifetime PlexPass, and I've also used Jellyfin for a few years. Like you said, Plex is better in the sense that it offers more, but they're also profit driven, which has become more annoying in the past few years.
Plex has way better logging than Jellyfin does, the latter suffers a lot from log spam, and the stack traces it produces when anything errors out are like 10-15 lines. They're not of use to end users, and there's no way to disable them/decrease the verbosity.