The integrated stepper motors are specifically designed for the needs of those who require a product already equipped with electronics with very small dimensions. In fact, they allow to reduce the wiring space and, moreover, to be able to optimize the costs compared to the solution with the motor separated from the drive components. Only the connecting cable for power and communication (or the sensor) is required.
https://www.ipcmotors.com/ipcproduct/motori-stepper-con-elettronica-integrata/