In the EU we’ve had energy labels for years and for a TV or fridge those labels have a function as a better label is better for your wallet. But phones don’t use a lot of energy. If the difference between A and C category is 1kwh/year that’s just € 0,10 - € 0,50 more a year. Even in low income countries you can’t buy anything for that. For a major appliance or a TV you can maybe save 100kwh a year and now we’re talking real money € 10,- is a new T-shirt of for low income families an extra day food. € 50,- will get you a good dinner in a restaurant if your electricity is expensive.