All regulations have unintended consequences. And the best intentions sometimes backfire. For example, take the new European standard for electrical consumption of vacuum cleaners. In essence they've now banned the larger models. But it's not going to save any electricity. Now with smaller models that can't create as much vacuum and thus induce a much smaller CFM of air flow. Hence they work less efficiently and more slowly. So any electrical efficiency gains are offset by the poorer performance overall, requiring longer use and just as much electricity. Besides that, even if all things were equal, the greater electrical use (and subsequent CO2 generation) from the bigger vacuums probably can't even be quantified for most people since vacuum cleaners are used so infrequently compared to computers, lights, heating, and other electrical devices.
This is, in my mind, a clear example of well-intentioned Energy Star -like programs and regulations that just don't apply well to many things and shouldn't. And this is why people, including trump supporters, get so upset with government interference in their lives. Most people I know aren't stupid. If they buy a new freezer, they do want to save money and energy by buying the newer, more efficient models. I think this would continue even without Energy Star, should it ever disappear entirely.
Besides that, if you really want to change things, a carbon tax is better than efficiency regulations. If the true cost of energy is passed on to consumers you can bet they'll make different choices and drive demand for energy-efficient devices. Rather than set fuel efficiency targets, tax a vehicle's registration based on its fuel consumption. Lets people have the freedom to drive an old, less-efficient vehicle if they wish, as long as they are willing to pay for it.
Sure direct regulation is easier for the government, but it's not always the best way. And it always has unintended consequences and leads to regulatory capture of the market by a few large companies.