The wonderful efficiency of surplus economies, in which the amount of goods produced isn't calculated to be efficient and to use them as needed, but instead everything is produced in excess as a consequence of demand-limited competition between companies. Fully stocked supermarkets with no shortage of anything whatsoever, basically require throwing away a given percentage of produce periodically.

This is discussed in a wonderful episode of The Deprogram podcast (with Second Thought, Hakim and Yugopnik) in which they bring in a guest to discuss economic planning, and the guest explains the difference between shortage (think USSR) economies and surplus (think US) economies, which explains both why there are bell peppers rotting in supermarkets in the US and why there were shortages and rationing of certain goods in the USSR (spoiler: both are political decisions)