Bitcoin mining uses a lot of energy, but its consumption is rarely put into context. Bitcoin mining is seen as a mean to process payments, and without a doubt if you put it in such context, Bitcoin is really inefficient, but Bitcoin mining is not primarily about processing payments, but securing a decentralized network, allowing uncensorable transactions worldwide.
The more people are mining Bitcoin, the harder it gets for any single actor to take control over the network and erase or censor transactions. In this way, Bitcoin payments are inherently different than regular Bank payments and serve a very different purpose. If you are living in most of the western developed countries, the primary use case for you is Bitcoin as an asset, not Bitcoin as a payment system. For the rest of the world, either having no access to banking, or reliant on banks in an authoritarian system, Bitcoin is the solution. And for them, the energy consumption is worth being able to escape a corrupt and fascist government.
Comparing Bitcoin to Banks in efficiency of energy consumption per transaction is as if you would compare an electric car to a tractor; of course, the tractor is not as fast as a Tesla and consumes more energy, but although both are on wheels and take you from A to B, their use case is very different.
But we haven’t even touched the other side of the equation. Centralized banks consume energy as well; a lot of energy. Massive skyscrapers of hundreds of banks around the world, being build, maintained, and filled with people every day. As you are your own Bank with Bitcoin, all of this in non-existent.
But more important than overall energy consumption is the sourcing of the energy; if the energy is coming from renewables or fossil fuels. And in contrary to Banks, Bitcoin mining favors and promotes a transition to renewables. Miners’ profit is determined by the price of electricity, and unless you live right next to a coal plant in China and illegally plug its energy, renewables are the cheapest. At the same time, Bitcoin functions as a storage for all excess energy from renewables that can’t be stored or used in the electricity grid, which turns it into an essential component in modern energy infrastructure.