Software is bought to handle a function: an ERP for transactions, a CRM for customers, a spreadsheet for everything neither of them covers. Each does its job.
But work arrives as a process that crosses all three, and the crossings are manual. Someone copies. Someone re-keys. Someone checks that the copy matched.
These steps are invisible in every system because no system owns them, and invisible in every budget because they are somebody’s afternoon rather than a line item. They are also, almost always, the cheapest thing in the business to fix.