There's a therapeutic window, and too little uncoupling is just as harmful as too much.
Too little uncoupling is almost universal; too much uncoupling may occur when climbing Mt. Everest, or from taking an overdose of chemical uncouplers.
The idea is that, within the therapeutic window, uncoupled respiration generates more CO2, and the increased level of CO2 is the real benefit.
Please note: I find that when I'm uncoupling, I need plenty of food and vitamins, or I may feel less energetic, not more.