Efficiency is a false god.
I've been saying that for a while, possibly decades now. It's interesting because folks, especially technical folk, tend to interpret me to mean an efficiency is false (ie the cake is a lie, not truly efficient) which is broadly true but not what I mean, or that efficiency will be used to bad ends, which is almost always true but not what I mean.
What I mean is that efficiency is itself a bad end. It's not a broad value. It will not light our way along paths to good.