I'm fairly certain that more money is spent to create & manage a single US dollar in circulation than is used for a single bitcoin unit. The latter has no paper form, no need to be physically lugged around, no ongoing R&D design overhead spent on counter-counterfeiting measures, no Department of Treasury budget costs, no Secret Service budget costs, no banks or bank vaults, no armored trucks with armed guards lugging money bags... I could go on but I'll stop.
To address from a different angle, the phenomenon where you say electricity is being "wasted" to produce a bitcoin is analogous to the creation of a US dollar. Not to the using of it or acquiring of it. You can buy and acquire a bitcoin fairly quickly and cheaply, CPU/electricity-wise. Much more so than if you had to "mine" it. Much like dollars. Much cheaper/easer/faster to "buy" a dollar than to construct one out of thin air. (A legal one, anyway.)
To address from a different angle, the phenomenon where you say electricity is being "wasted" to produce a bitcoin is analogous to the creation of a US dollar. Not to the using of it or acquiring of it. You can buy and acquire a bitcoin fairly quickly and cheaply, CPU/electricity-wise. Much more so than if you had to "mine" it. Much like dollars. Much cheaper/easer/faster to "buy" a dollar than to construct one out of thin air. (A legal one, anyway.)