I don't know, but the infrastructure for fiat currencies can achieve efficiency gains through scale. Bitcoin cannot, on a very fundamental level: energy expend

I don't know, but the infrastructure for fiat currencies can achieve efficiency gains through scale. Bitcoin cannot, on a very fundamental level: energy expenditure for mining must at all times be so high that an attack is financially unattractive. So energy usage has to increase linearly with the market cap - and completely independant of how many transactions there are.