It’s not perfect but the battery menu on macOS pointing out apps consuming a lot of energy has inspired a good amount of efficiency work for macOS ports of things because users see it and gripe at developers about it.
I would like to see that taken a step further. Something like the system showing a notification banner saying something to the effect of, “BadApp is consuming excessive amounts of energy. Quitting it will increase your battery life by approximately 3 hours and 15 minutes.” I believe quantifying the loss that the user is suffering as a result of the developer’s laziness will go a long way to inspire displeasure in users, who will then apply pressure on developers to fix it and opens up space for competitors who sell themselves with better efficiency.