Does the below quote really mean that there's only 8% power drop from the charger to the battery? That too good to be true with a wireless system, even with dir

Does the below quote really mean that there's only 8% power drop from the charger to the battery? That too good to be true with a wireless system, even with directional antennae. "In their new paper, the researchers show how to boosts the system’s wireless-transmission efficiency to 92%. The key, Assawaworrarit explained, was to replace the original amplifier with a far more efficient “switch mode” amplifier."