It has become a commonplace to describe the Microsoft 365 Ribbon as the finest office interface available — the most polished to look at and the most ergonomic to use. The claim is repeated so often that it tends to pass unexamined. It deserves examining, because hidden inside it is an assumption that quietly does most of the work: the idea that there exists a single best interface at all. A competent design — for one kind of user Let us begin by granting what is true. The Ribbon is a capable piece of design. It was built to help an occasional or intermediate user discover features by browsing rather than by memorising, and for that user it does its job well. Saying so is not a concession wrung out reluctantly; it is simply accurate, and any honest discussion should start there. But “well-designed for a particular user” is not the same thing as “best interface,” and treating the two as equivalent is where the reasoning slips. An interface optimised for one persona is, by construction, less suited to the others: the power user who works from the keyboard and resents losing vertical screen space, the migrating user carrying twenty