Former banker here. There's extremely little overlap between traditional banking and what cryptocurrency does. There's more overlap with what a credit card co

Former banker here. There's extremely little overlap between traditional banking and what cryptocurrency does. There's more overlap with what a credit card company does. Most of traditional banking is about financing, not about money transfer. The risk estimation and risk control are the tough parts of financing, and I don't see how on-chain computation is a good fit for that risk modeling. So, "What's the energy cost of the combined Visa and Mastercard networks" is a much better benchmark than "What's the combined energy cost of the traditional banking system?" One big energy use I optimized was daily risk calculation for exotic books. Say an Australian insurance company sold a bunch of life insurance in Japan. They want to cap their losses on $5 billion USD notional (maybe 2,500 policies, each for $2 million) over the next 30 years, and they want to cap their losses at $1.5 billion AUD. This extremely bespoke, not something the bank can offload to another entity, so the bank is pretty much stuck with this re-insurance on its books for the next 30 years. How much does the bank need to keep on-hand in case this goes sour? To answer that question, every day the bank needs to run Monte Carlo simulations to cover shifts in the Japanese life expectancy curve and shifts in the JPY/AUD exchange rate over the next 30 years. It turns out that for some of these exotic options contracts, just compute cost for calculating risk exposure over the lifetime of the trade can end up being a noticeable percentage of the profit from the trade. Sure, you could pull some of that simulation compute on-chain in smart contracts, but what does a DAO do when it has insufficient reserves to cover its outstanding obligations? I guess you need a diverse enough DAO so its risk exposures are sufficiently uncorrelated, but that means that it needs to do vastly more computation to calculate its current exposure every time someone asks the DAO to enter into an obligation. Either all miners need to redundantly run these calculations, or you push them off-chain. If you push the risk calculations off-chain, then you're back to the energy consumption being very different than the traditional banking system.