That's a matter of perspective. Are you comparing to copper or to other electrically isolated power transmission tech? A typical LED is 40% efficient and a typ

That's a matter of perspective. Are you comparing to copper or to other electrically isolated power transmission tech? A typical LED is 40% efficient and a typical solar panel is ~20% efficient. A typical Qi charger is ~50% efficient. I stopped using cables for portable devices a few years ago and use magsafe instead which is supposedly has 75% efficiency due to perfect alignment of the coils, but that's still nowhere close to the ~100% you get from copper cables.