Other cryptocurrencies like Ethereum, which are far more energy efficient than Bitcoin
Calling those that don't depend on proof-of-work "more energy efficient" is understating it to the point of being dishonest. The difference is not that they're more efficient in any conventional way. It's that they don't have the amazing bitcoin feature of relying for their operation on the practice of deliberately wasting enormous amounts of energy for the purpose of being able to prove that you've wasted enormous amounts of energy.
All the way through the cryptocurrency crash which the average reader of headlines might've thought had put an end to it by now, the bitcoin network has kept on burning up absurd amounts of power.