X-inefficiency only looks at the outputs that are produced with given inputs. It doesn't take account of whether the inputs are the best ones to be using, or whether the outputs are the best ones to be producing. For example, a firm that employs brain surgeons to dig ditches might still be X-efficient, even though reallocating the brain surgeons to curing the sick would be more efficient for society overall. In this sense, X-inefficiency focuses on productive efficiency and minimising costs rather than allocative efficiency and maximising welfare. For more extensive discussions, see Sickles and Zelenyuk (2019, p. 1-8, 469) and references therein.