200 GWh/year is a little less than 23 MW. A full power plant is on the order of several hundred MW to around a GW. You also don't need to replace the power plant every year. I agree that standby power usage is terribly wasteful but your calculation is off by a large factor.
Given the Jevons Paradox, we can predict that the lower energy use will translate to higher demand for IoT technologies, thus increasing the world energy requirements for these devices.
