Bitcoin consumes 'more electricity than Argentina'
Also the equipment used to mine cryptocurrencies doesn't magically appear. What percentage of the world's mining operations for copper, lithium, silver, etc. goes to building crypto-mining rigs? How does that total output compare to the 3k tons of gold?
[1] - https://www.visualcapitalist.com/wp-content/uploads/2020/03/...
I don't know how much of that $75B/year translates to CO2 emissions, etc, or how it compares to BTC or what have you, but you can buy a lot of externalities for $75B.
I'd put my estimate at something like 30-150 megatons of CO2/year for gold, just because I'd be surprised if they spent less than 10% of the cost of mining gold on fuel, or more than 50%. So I'd be neither surprised if gold generated less CO2 / year than Bitcoin, or if it generated like 4x more.
Bitcoin is a ten year old project, written in mutable code, that's invisible, intangible, and essentially replicable by any number of competing crypto projects or forks. It may be useful, or it may not be. It may stick around, or it may disappear. Either way, it's not seriously comparable to gold.
The same cannot be said for BTC.