You mean p-states in your first sentence, right? Anything but c0 represents different levels of 'retiring no instructions' (totally idle). The rest of your comment seems accurate though.
The author mentioned blinking cursor, so it reminded me of graphics issues. A more efficient CPU state has the possibility of slowing an app due to CPU-GPU sync points. A blocking CPU in an energy efficient state can reawaken slower from GPU done notifications, so FPS is lower. So both c-state and p-states can affect performance. General point was just utilization may not be utilization at max power.
I've worked on problems where utilization was 15% at lower power and it was a problem. But to compare different workloads, it'd be < 1% at max power.