Some DLC PKGs contain files for future content that is locked on disc. Extraction can reveal hidden models or levels.
If you have a custom firmware (CFW) or HEN-enabled PS3: pkg extractor ps3
Archivists argue that extracting PKGs is essential for preserving PS3 software, especially as PSN storefronts close. The Video Game History Foundation and Internet Archive have used PKG extractors to dump game data for research. Some DLC PKGs contain files for future content