That, like elsewhere, is a naive view of efficiency - in the same way trying to apply mathematical logic to reality is a naive approach. Just like reality is best modeled in probabilistic terms, optimization can be done on probabilistic models. Redundancy comes out of it naturally, if you put costs and uncertainties in your models.
For any uncertainty you have not modeled, _you must have slack in the system_. This is true of your personal workflow, your professional environment, your romantic life, your business. If you aim only for optimization, you are implicitly optimizing _for the things you have modeled_ - this can often come at the cost of the things you have not.
I would say that, perhaps loosely, optimization is the delusion of overconfidence. Slightly less optimization, and more redundancy, is good caution.
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