How much research have you actually done? I was studying this very topic two days ago.
The global banking system uses 4x more electricity than bitcoin does and is nowhere near as safe.
Though I do agree they both use a lot of electricity.
The problem is how the electricity is made and not so much about how much is needed.

Bitcoin - 32.56 TWh Global baning system - 140TWh

https://medium.com/@zodhyatech/which-consumes-more-power-banks-or-bitcoins-8302750fe2bc