If there are a number of torque wrenches in a workshop they can be checked roughly against each other. If one is massively out it probably needs recalibration.
True; and in a good workshop (that doesn't abuse them by dropping them etc.) they're likely to be used often enough to stop them gumming up. For home mechanics that only torque stuff up once in a blue moon the breakaway torque can be significantly off.
If there are a number of torque wrenches in a workshop they can be checked roughly against each other. If one is massively out it probably needs recalibration.