I am not sure the alternative (traditional banking) is so co2 neutral. As far as I know they all have plenty of huge buildings with hundreds of people wasting their time & resources working for them.
Don't get me wrong I am sure bitcoin is worse in terms of power usage, but not every crypto is automatically worse than what we have right now.
You can see it as an idiotic PoW for all those people working in those banks.
It's easy to make it renewable with benefits to us. The solar panel on a bank building is giving energy to people.
And I'm not saying that the current banking system is perfect (it actually optimizes itself quite well) but it has much more features while Bitcoin/crypto doesn't have real solutions for huge issues.
Fraud, scams, money laundry, investment tools, sepa, bank account recovery, global market regulations, sanctions Support etc.
And it does all of that with billions and billions of assets.
While Bitcoin consumes energy.
In an utopian society we don't need banks and no PoW crypto but that's not what is critical now.
Besides aluminum smelter, due to high energy costs there are other critical industry affected as well: paper making and glass making. Bottles for example.
Don't get me wrong I am sure bitcoin is worse in terms of power usage, but not every crypto is automatically worse than what we have right now.