That fact just makes the enormous use of power on Bitcoin look even worse though. The main rebuttal to the Bitcoin power complaint is "but it's useful as a decentralised currency." If there are other cryptocurrencies out there doing the same thing using orders of magnitude less power, where does that put Bitcoin?

We have a technology that takes thousands - by some measures hundreds of thousands - of times as much power as existing networks for one transaction, that isn't used in a practical day-to-day sense anywhere, and many people are still defending Bitcoin specifically as a successful currency. How much power does it have to consume, how few real-world uses does it have to have, before everyone agrees it could really do with some improvements?