Most over-packing comes from planning for a version of the trip that doesn’t happen — the dinner that gets cancelled, the “just in case” outfit for an event that was never actually on the itinerary.
The Real Rule
A short trip rarely needs more than what fits in a carry-on: one outfit per working day, one pair of shoes versatile enough for both meetings and dinner, and whatever actually charges your devices. Everything beyond that is usually insurance against a scenario that’s more imagined than likely.

Laundry, not luggage, is the real answer to a trip running longer than planned. A hotel that offers same-day laundry effectively doubles a small bag’s usefulness — worth checking before assuming more suitcase is the solution.
Where the Upside Compounds

No baggage claim means no risk of a delayed bag derailing the first meeting of the trip. It also means moving through an airport, and later a hotel lobby, without wrestling a case that’s heavier than it needed to be.
The guests who travel lightest tend to have the calmest first hour in a new city — no lost-luggage form to fill out, no waiting at a carousel while a taxi meter runs outside. It’s a small discipline that pays off disproportionately.