Bitcoin and similar algorithms that rely on PoW or mining are notorious for being power hungry, wasteful and unsustainable. Many argue that in reality the fiat system as a whole still uses more energy or resources to keep the system running. First of all fiat takes time, energy and money to produce the currency. Then there is the energy to run the ATM and SWIFT network, transport and store the cash. The argument is that as a whole fiat takes more energy and resources to function compared to Bitcoin.
This may be true but Bitcoin will continue to consume more energy to produce less coins as difficulty spikes.
On top of that there are more efficient algorithms that use less power to mine. There are also newer PoS/Proof of Stake algorithms that use almost no power especially compared to mining.
It may well be true that Bitcoin as a whole uses less energy than fiat but it doesn’t mean we should accept the status quo of wasting energy.