A lot of people with tech backgrounds seem pretty pro-Vaporfly. As a (former?) competitive runner you might find my anti-Vaporfly perspective interesting.

To me, running is a non-mechanically-aided sport. The moment a shoe attempts to store and return mechanical energy in the stride, to me, that's a different sport.

We already know that people can go faster and farther with mechanical aid, if you use big enough springs on your feet. Look at the discussion around Pistorius' blades. Let alone something like putting wheels on your shoes.

So we know from first principles that there's going to be some limit to the mechanical advantage that footwear is allowed to provide. The only question is where to draw the line.

Now you could draw the line at providing any mechanical advantage at all, and keep the sport the same as it's been since the dawn of time. Or you could draw the line a little bit farther along, making the sport partially about the runner and partially about the technology. I see no coherent reason to do the latter, except for shoe companies' profits. It hurts the fairness of the sport, it takes a bunch of fun out of it, it transfers a whole bunch of money from a previously-dirt-cheap sport to the shoe companies, etc.