Software gets bought the way it gets used: one person needs a tool, expenses it, and moves on. There is no moment in the calendar where somebody sits down and reads the full list of what the company pays for every month. The list only exists in fragments - a card statement here, an invoice folder there, a plan somebody chose in 2023.
Renewals arrive without a decision. Annual plans are the expensive ones, and they renew eleven months after anyone last thought about the tool. By the time the invoice appears, the money is gone and the refund window has usually closed.
Bank statements hide the details. Software billed through Stripe, an app store, or a reseller shows up under a merchant name that has nothing to do with the product. Your accounting export tells you money left; it does not reliably tell you what for.
Per-seat pricing drifts upward. Seats get added during a busy month and stay added. The unit price never changes, so nothing looks wrong - the total simply grows a little each quarter.