Where to begin? You can't talk about efficiency without talking about the productive output. If I spend 200x as much to get 200x as much value, the efficiency

Where to begin? You can't talk about efficiency without talking about the productive output. If I spend 200x as much to get 200x as much value, the efficiency is the same. The productive output of the USA includes keeping about 330 million people alive with a decently high standard of living. The productive output of bitcoin is enabling speculation, money laundering, and crimes such as ransomware. There is no rational world where the two levels of output are even remotely in the same ballpark. So let's try to compare them properly. What is secured by US manufacturing is NOT the USD, but the US economy. Which according to https://en.wikipedia.org/wiki/Financial_position_of_the_United_States https://en.wikipedia.org/wiki/Financial_position_of_the_Unit... has a net worth of over $120 trillion. What is secured by bitcoin mining is the existence of bitcoin. Which currently has a market cap of a bit under $600 billion. This values the US economy at 200x bitcoin. So if the US economy takes 200x the energy, that's THE SAME level of efficiency. But it gets worse. As others have noted, it is widely believed that bitcoin is a speculative bubble which rounds to "the largest Ponzi scheme in history". To get bitcoin mining to be equal in efficiency to US manufacturing, you have to accept an almost certainly fake valuation for bitcoin at face value. If you don't accept the paper valuation as being real, then bitcoin's efficiency drops dramatically.