The doctors could at most only see the beginning of the trachea with the opportunity, which meant the view was very limited, and there was no hope of seeing the tracheal bifurcation. The tracheal bifurcation is the place where the trachea splits into the left and right main bronchi, at the very end of the trachea.
If their group of doctors' speculation is correct, the cotton ball blocking the child's tracheal bifurcation is invisible with a direct laryngoscopy.
The greatest function of the direct laryngoscope is actually to open the glottis to expose the trachea, giving the foreign body forceps a chance to enter the trachea for operation. The forceps have a head with an open-close tip that experienced doctors estimate the inserted length and rely on tactile sensation to pinch, which is blind operation.
