Dark data is the information companies collect but never use—often making up...

https://weekly-wiki.win/index.php/How_Do_I_Find_Former_Employee_Folders_That_Nobody_Owns_Now%3F

Dark data is the information companies collect but never use—often making up 60-80% of their stored data. This unused data takes up space, slows systems, and can cost businesses over $2.5 million each year in wasted storage and management