Maybe not strictly software, although it's clear that the range of what's possible to do in software is only getting wider. It still doesn't preclude from involving people, and improving the quality of service.
Yes you could create a more energy efficient bank, but that is orthogonal to that bank using bitcoin. Many people have tried, but most have failed. Those that succeed are generally acquired and the bigger banks tend to (albeit slowly) integrate those efficiencies.
The post I was replying to originally was citing an article claiming that the energy costs of holding dollars and gold was higher then bitcoin. I was showing how tallying the total energy used by global banks was a false equivalency as much of what a bank does has no direct equivalent in the numbers given for Bitcoin.