No idea about which specific type of business it is, but keeping that history long term can have some benefits, especially to outside people. Some government agencies require companies to keep records for a certain number of years. It could also help out in legal investigations many years in the future and show any auditors you keep good records. From a historical perspective, it can be matched to census, birth, and death certificates. A lot of generational history gets lost.
Companies also just hoard data. Never know what will be useful later. shrug