What happens if an object impacts a touchscreen and it breaks? I have my screens break (even behind a screen protector) and has failed to respond to touch. Imagine you are flying a plane and the touchscreen breaks due to impact. All your inputs are centralized behind that one touchscreen and you can no longer operate it. Wouldn't it be then better if there were multiple points of failure? You are decentralizing the impact a failure can have. Sometimes having multiple points of failure is a good thing. That way a failure in one component won't affect the other components.