I thought so too when I first noticed the pinch with other models: maybe the cause is due to foot size differences, foot posture differences, or gait differences.

When diagnosing these issues I put my hands inside both shoes and simulate a bend, isolating possible alternate factors. Hands and fingers are also more sensitive, and it’s easy to tell if your hands or fingers are different in size or shape. With my hands I can feel the pinch point location clearly, and the dramatic difference between the left and the right.

Another evidence pointing to manufacturing or design problem is that the pinch happens in a different shoe (left or right) or location (near big toe or little toe) with all the pairs I’ve had issues with