I kinda get the "evolution-barefoot" hypothesis.
That said, we weren't designed to run on concrete?
When I was younger, I ran toes-to heel, in the 80's. I just thought it made the most sense. I had an accident where I shaved all the skin off my Achilles' tendon. I also shaved off 1/4 of my Achilles' tendon. That ended my running style, along with 20 lbs of fat.
Now my sister was just running around a baseball diamond when her achilles tendon snapped. She told me she was mimicking my running style. She just heard a pop, and felt no pain until she got up.
My point is I don't know if they have definitively figured out the best running footware, or even technique. I will say this, gaining weight was the worst thing I ever did for my runnng. Just a few pounds, really ended my running.
(On a plus, when I walk now, I'm carrying around a sack of potatoes. I still get that running high. I do need to walk up hills though. )