To power up over a network would need the Ethernet and/or WiFi powered up and a computer running to listen for the command. There are requirements (look up ENERGY STAR) when the power is off that means that this can't happen. The old IR system was very low power so that's why that worked back then and now.

So in the big scheme of things, all you wrote sounds right. Bluetooth might be low power enough but very few sets would have such.