I disagree with this argument. You are posing two extremes: One where everything can be known with certainty, and one where everything is purely based on faith,

I disagree with this argument. You are posing two extremes: One where everything can be known with certainty, and one where everything is purely based on faith, and dismissing the potential of there being something in the middle. You are right, economics can't model every potential variable that influences outcomes. Large scale studies of minimum wage admit that policy and economic differences between local municipalities can cause the effect of a minimum wage change to vary. But you can model for most major differences, such as "Did adjacent municipalities adjust their wages at the same time? Did this have an impact on employment". Ultimately you can get much closer to an understanding of how minimum wage impacts an economy than you would from a purely faith based approach, and you can land at a recommendation like "In general small increases in the minimum wage do not raise prices or hurt employment, given the following conditions". That's much more valuable than the Austrian position that purely bases itself on faith.