For a small number of simple AI uses, a spreadsheet may be enough. It becomes harder to rely on when the organisation needs people to contribute information, complete reviews, store evidence, track actions and report changes over time.
What spreadsheets do well
They are familiar, quick to set up and useful for an early inventory. They can record the product, purpose, owner and status of a limited number of uses.
Where the limits appear
As the portfolio grows, the work around the list becomes the problem. Teams need reminders, ownership, evidence, approval history and a consistent way to assess new or changed uses. Reporting then involves checking several disconnected sources.
Choose based on the work you need to maintain
Move beyond a spreadsheet when the register needs to support regular discovery, repeatable reviews, assigned actions, supplier information, evidence and board reporting from the same current record.