I'll say that not having to do that is a major postiive. One of the UX things that bounced me off of jellyfin was ending up with a reconfigured library. The correct UX choice is for the software to adapt to your preexisting library, not having to rebuild it all with a different set of information files and naming conventions.
That is a BIG deal when you have a big library. Also why I hate Calibre. Screw Calibre.