I think we probably both agree that resin codes are originally and principally manufacturing specs. I don’t know how many (lay) people correctly use them to guide how they should dispose of things. My biggest point though is that however resin codes were started, they have been taken over by a corporate desire to make things that aren’t recyclable look recyclable. They give a facade of recycl-ability, so that plastic keeps being produced. People are also encouraged/tricked to put garbage that bears look-alike recycle codes into their municipal recycling. As a result, recycled plastics are contaminated, become garbage, and more new plastics are generated.