The big improvement then was a carbon plate. Adidas (and others) followed suit. The subsequent improvements since then have been marginal but the margins are thin at that level. In this case the big advancement has been the weight of the shoe.
EDIT: Also it's worth noting these shoes are $500 retail. Adidas will for sure get a boost in sales from this, but there's definitely competition in the $200~$300 marathon running shoe space that won't solely draw everyone to Adidas)
I think the big story here may be the nutrition science to get these guys to absorb a lot of carbs during the run, more than the shoes.
Essentially the argument given was too much advantage came from the shoes and they didn't want racing to be about shoe technology development.
The advancements in shoes have made a measurable impact, but there are lots of optimizations being worked on.
But yeah at this point, “it’s the shoes, stupid” should defo be the main part of the conversation.
Or did the AI say we should be using PVA/cyanoacrylate/polyurethane glue or something?