dc brushless motor is a typical mechatronics product which has many advantages, but it also has some disadvantages.
The disadvantages are :
The electronic speed controller (ESC) rectifier motor is needed. Additional equipment is usually required to provide throttling signals to ESC.
If ESC sensor less (favorite) rarely start torque.
ESC is designed with rotor position sensors (usually Hall effect devices) that give good starting torque, like brush motors.
Some small dc brushless motors have built-in controllers, but most large motors require separate controllers. This increases the cost and complexity of the motor solution.
You may also need a sensor to tell the dc brushless motor controller the angle of the motor shaft, although there are now sensorless motor controllers that can use motor coils as sensors to detect the angle of the motor.
The brush motor automatically completes the switch through the commutator assembly. Since the dc brushless motor does not have a commutator, it will require some electronic equipment, usually involving six MOSFETs and a microcontroller or similar arrangement to do this. Therefore, the main disadvantage of dc brushless motor is that it needs an electronic switch controller to synchronize the voltage and motor rotation to the motor coil.