Admittedly, shoes don't pass the third point as you can just step out of them after the competition, even if they were unhealthy. But still - if extremely optimized hi-tech running shoes are allowed, why not go one step further and add motorized rollers? Where would be the difference?
(This is an actual issue in biking, btw. You could also ask why relentlessly optimizing your bike for low weight and air resistance is allowed, but adding hidden motors is not)