Dark data is all the information companies collect but never use—about 60-80%...

https://domgodwinson38.gumroad.com/p/why-do-ai-answers-hallucinate-when-there-are-duplicate-documents

Dark data is all the information companies collect but never use—about 60-80% of it just sits untouched. This hidden data piles up quietly, causing clutter and driving up storage costs