I think "masseprodukt" or "masseproduserte varer" (from "masseproduksjon") fits the bill. High street fashion/products/banking is a very UK specific term. It's meaning is to signal that the product/service in question is widespread/widely accessible for mass consumption, as opposed to niche/specialised providers. In UK towns & cities, big brands would typically occupy prime locations along the main street (high street). More independent specialists would normally not be found directly on the high street. Hence the metaphor.