This is exactly the problem. Consider an order processing system that processes a million orders a day, and retains them for ninety days. What percentage of those 89-day-old orders are actually needed at 89 days old? It could be quite low, maybe a couple thousand out of a million.
But if those orders aren't there, shit hits the fan. PCI compliance audits fail. The ability for customers to reconcile their charges with their purchases breaks. In that 0.01% of cases where the order was fraudulent, placed by mistake, or just didn't have what the customer thought it had in it, not having that data makes the order processor read as, if not malicious, at least incompetent.
The real question is, how much data do we need to store inefficiently, in a way that uses a lot of power and space?
But if those orders aren't there, shit hits the fan. PCI compliance audits fail. The ability for customers to reconcile their charges with their purchases breaks. In that 0.01% of cases where the order was fraudulent, placed by mistake, or just didn't have what the customer thought it had in it, not having that data makes the order processor read as, if not malicious, at least incompetent.
The real question is, how much data do we need to store inefficiently, in a way that uses a lot of power and space?