Brands use them for range and continuity. A cast can cover the sizes, ages and skin tones a customer base needs, and the same face can appear on every product for years without rebooking. Because no real person is photographed, there is no day rate per shoot and no private individual's likeness in the picture.
The quality test is skin and fit. Visible pores, flyaway hair, natural hands and fabric that follows the body separate a believable model from a glossy render. A face that shifts between shots, a common failure when brands run AI themselves, breaks the catalogue. The LoRA entry explains how a face is held steady.
