I believe much has to do with the efficiency of the refrigerator itself and its ability to exchange the air.
I have a well insulated garage and bought a separate refrigerator solely for aging meats and drying sausages. I have a lot of stuff in there from sirloins to sausages to whole loins, bresaola and capicola. I have never experienced an absence of bark on loins or rib eyes, nor has there ever been evidence of mold on anything.
Maybe I’m just lucky.