There's an interesting snippet in the BBC article regarding the Cambridge Bitcoin power study:
However, it also suggests the amount of electricity consumed every year by always-on but inactive home devices in the US alone could power the entire Bitcoin network for a year.
If we're talking about wasted electricity, how about the global impact of everyone leaving their TVs, monitors, etc. on stand-by because they can't be bothered to press the power button?
It's also worth bearing in mind what this study actually says. They've estimated the live power consumption of Bitcoin mining (Bitcoin only), within very wide bands (currently 5.28GW to 58.02GW, with an estimate of 16.87GW). They then take a 7-day rolling average of their estimate, and use that to calculate annual figure.
If their estimate is correct,
and power consumption stays at those levels for a whole year,
then annual electricity consumption for Bitcoin mining might be higher than the annual electricity consumption of Argentina (in 2016). But consumption isn't stable; it's gone up roughly 2x in two months.
Either way, mining clearly uses a colossal amount of power. But I doubt there are many in the developed world who can get on their high horse about it without being somewhat hypocritical. We all waste a colossal amount of power daily.