Think in terms of energy per symbol and it makes sense. When waiting in rcv mode you're paying energy for zero symbols. The other is transmitting short packets

Think in terms of energy per symbol and it makes sense. When waiting in rcv mode you're paying energy for zero symbols. The other is transmitting short packets at high power/data rate is a win vs low power low data rate long packets because your energy per symbol is lower with the former. And people that show know better seem to make that mistake a lot.