Why does Swiss tax vary so much by canton and municipality?
Switzerland has no flat national income tax rate. Federal tax is the same everywhere, but each of the 26 cantons sets its own tax schedule and multiplier (Steuerfuss), and each municipality within a canton then applies its own separate multiplier on top. The result is that two people earning the same salary can have meaningfully different take-home pay depending on which canton and which municipality they live in: low-tax cantons like Zug or Schwyz can differ from higher-tax cantons like Geneva or Basel by many percentage points.