Those shoes are gonna sell like crazy now but it would be hilarious if they were to be found to have been giving an unfair advantage because of some mechanical property of the shoe.
Reviews say that they have very very good, but not record breaking energy return and shock absorption. But what they are is insanely light at sub 100g.
For a while it was all about getting the lightest shoes, because picking up heavy shoes slowed you down. Then the energy return (pebax foam, carbon plates/rods) became the main focus because the weight didn't matter as much when the shoe was literally springy. Surely this is now going to spark a race for the optimal balance between weight and energy return.
I can absolutely imagine that the "correct" balance varies from one person to another, and yet that this is both measurable and also irrelevant for non-pro athletes.
Like the number one endurance runner in the world will get a minute off their marathon time because a shoe manufacturer spent $1M making custom shoes for that athlete which don't even have a size they're just "For this one specific person, now" but then some guy on Reddit wants better shoes because he's sure his four hour marathon would have been "more like three" if he had those elite shoes instead of the $100 Nikes he wore...
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)
Well, the marathon record has been broken 53 times since the early 1900s. So, there are a lot of factors at play. Better training, better nutrition, better tactics, and, yes, better shoes.
The advancements in shoes have made a measurable impact, but there are lots of optimizations being worked on.
Also population and access. In the time since the early 1900s a lot more humans exist, and more of them have the opportunity to attempt this record. Population in Africa exploded in that time and access improved significantly.
If you're bloody quick and born in Birmingham (either of them) in 1900 you can probably find out about and get yourself a chance to attempt that world record, but if you're born in Kapsabet (in Kenya) in 1900 good luck, even in Nairobi I wouldn't bet on it.
https://runrepeat.com/adidas-adizero-adios-pro-evo-3