Bitcoin's not a waste of energy at all. Think about it. How much power do you think every single bank facility and banking-related office building in the world uses up each day?

I'd wager if you were to see a direct comparison between the total daily power consumption of Bitcoin's PoW and the average daily power consumption of, say, Goldman Sachs... you would then find the statement "Bitcoin's PoW is a waste of energy" completely laughable.