A well-wrapped building requires (mandates in fact) a form of mechanical ventilation... which itself needs to be correctly sized and well thought out. My personal view is that as we increase the insulation in a house, leaving it "leaky" becomes less of an option. Putting 30+cm of insulation in walls serves no purpose if you allow uncontrolled airflow. Mechanical ventilation also allows you to introduce fresh air where it is required, which may not correspond with the placement of windows and to ensure a logical airflow throughout the house, where humid air (such as in a bathroom / kitchen) is not circulated through "dry" rooms before being extracted. Here in Europe, passive houses are fitted with mechanical ventilation systems that extract calories from the "used" air and thus pre-heat the incoming air, and the remaining heat in the air is passed through a heat pump to be used for heating domestic hot water. This is admittedly a highly-technological solution.

If you're prepared to treat the envelope as a "living" structure where low-cost walls can be cheaply replaced or rebuilt as necessary (straw bale + clay render for example) then to a certain degree the risks of moisture incursion can be ignored as the material cost (environmental and monetary) is low, but this has to be considered as a part of the ongoing maintenance of the building.