I think it should be banned.
A lot of people think that all shoes have a spring-like effect due to energy return, and that is probably the case. But the Vaporfly does it in a different way.
The carbon fiber plate is shaped in a way to release the energy in a way which aids movements that is already happening. Other shoes don't do this. Don't believe me? It's right here in the patent:
This means that the energy return is actually engineered to be effective in the Vaporfly.
And if it was not effective, then there would not be so many runners using it and obsessing over its benefits.
The winners should be the ones who are the fastest runners, not the ones wearing the fastest shoes.