It's less about the web and more about the computations we're running. The stack end-to-end is inefficient because software quality is lackluster and deficient

It's less about the web and more about the computations we're running. The stack end-to-end is inefficient because software quality is lackluster and deficient of craftsmanship. This is mostly because the hardware enabled this type of behavior. The only way this is going to change is to change the hardware. I see this becoming possible as we transition to localized manufacturing where the individual only depends on themselves. So as we get closer to chip fab happening via a 3d printer, and all hardware and software being local, we'll be closer to the energy efficiency goal. You can see the trajectory already happening and IoT/Microcontroller/Etc boom. Lots of cool new projects are coming out with the "hacker-like" culture of old on energy efficient chips that can run amazing software powered by just solar alone. Super cool, I have faith we'll get there soon!