Usual army-based money depends weakly on the cost of energy, in general the economic structure of our society is ultimately based on trust of others and of the system.
Security of assets is understood to be best effort and preventive measures are well known to be unreliable (often replaced by inefficient punitive measures).
Bitcoin strives to build a trustless economy and thus its operation has far greater costs (fraud prevention with usual money generally costs proportionally with fraud attempts, while bitcoin is constantly tuned to 100% prevention).
In a more fair comparison we should compare the cost of all the world police + law enforcement + armies to the cost of mining energy + mining hardware and even given conservative estimates of corruption it isn't clear which side would be better under the total cost metric.
We could stop here and consider bitcoin an (almost) infallible trustless economy based on burning commodities compared to our usual fallible economy based on trust and force.
Personally I fell that this comparison suggest that bitcoin _should_ remain like it is today, relatively small with little influence on the world as a whole but readily available to who might need its peculiar service.
Bitcoin