Vintages mark the point where the crafting materials required to make items were reduced, as well as the inability to have bought them from the store and thus only available via hard-earned drops and crafting, marking them as items that potentially required more resources to create than they do now
While headgear's 3 refined recipe didn't diminish, it required 3 weapons instead of 2 to craft a scrap metal, equaling 81 items to create one hat back then while it only costs 54 now