I'm pretty sure the FaceTime camera is wired up to the T1 chip so apple can avoid an extra 3rd party part that connects the camera to the system via USB.
Those 3rd party USB webcam chips are also notoriously bad for image quality. This way apple has total control over the image processing of the camera, using the same technology/software they use on the iPhone.
Those 3rd party USB webcam chips are also notoriously bad for image quality. This way apple has total control over the image processing of the camera, using the same technology/software they use on the iPhone.