The Landauer limit is presumed to be a real limit to electronic computation: changing a 1 to a 0 releases energy that can't be sent out on the negative so it's wasted as thermal energy.

Photonic computing, graphene computing, counterfactual computing, superconductors, and probably edge chiral currents do or will eventually do more computation per unit of energy.

Ops per wHr metrics quantify the difference.