Sorry, maybe that was a knee jerk.
Don't get me wrong. I like jellyfin and I try to use it over Plex most days. But it does have out-of-the-box issues.
I've installed jellyfin several times with both docker and bare metal methods over the last 4 years. The transcodes have been an issue every time.
Maybe its my usage, but watching roughly 5 episodes of a show fills up roughly 3gb of the /var/lib/jellyfin/transcodes folder. In a 4gb container image, that's death. Jellyfin is the only container I need to expand to 16gb to adequately deal with this.
The default transcodes cleanup task is limited to every 24h at smallest interval, the option "delete segments" does absolutely nothing (I've watched).
I don't disagree that logrotate is a sensible answer here, but making that the responsibility of the user is silly.