Businessweek | The Big Take Why We Can’t Quit ExcelMicrosoft’s spreadsheet software is expensive, derivative and depressing. It might also be the most killer app of all time.December 4, 2025 at 5:00 PM ESTBefore it took over her life, Leila Gharani mostly took Microsoft Excel for granted. She was working on a process optimization project for a large paper-products manufacturer—a job that, to hear her tell it, sounds not entirely dissimilar from the fictional work depicted at Dunder Mifflin on Th...