It won't be interesting until shoes are such a decisive benefit that runners are pulling over to change into a new pair during the race itself. I don't see why we can't reach that stage. Obviously it's already a massive variable in auto racing, with new tires.
And likewise in cross country skiing with changing stations and opportunity to switch into skis with fresh wax. In fact, it's always a huge topic in those races as each major player approaches the area. Commentators will debate the benefit of fresh wax to the time lost in the changing station.