I know that mileage isn't everything, but when you compare it to the consistently really fast areas (Africans and Japanese runners), we run almost nothing. Here are some mpw our pros ran before their fall marathons this year:
Ben True hit one 130 mile week, but was mostly under 120
Noah Droddy peaked at 105
John Raneri was similar to Ben True, but more consistently close to 120
Colin Bennie peaked at 120, but was also consistent
CJ Albertson peaked at 120 but wasn't consistently high
Colin Mickow actually ran very high mileage hitting 150 and being around 120 or higher, but it looks more like crash training since he bike 200+ mile weeks right before that
Reed Fischer peaked at 115 and usually ran like 105
Zach Panning ran close to 130 and was usually more near 115, but he was consistent there.
Now, this may also be partly due to the trials this past June, but I feel like our PRO marathoners find higher than 130 to be crazy, and for some, even running much higher than 110 is hard to consistently do. I'm doing a pretty good job of armchair coaching right now, but I can't help but think that maybe if our elites ran more, we'd actually have guys under 2:10 more consistently. Heck, Ben True is a 13:02 guy, or even just a 13:22 guy this year... That should be plenty of speed to go sub 2:10.
To finish, I'm not trying to say these guys aren't fast, they are. 5:0x pace for a marathon is crazy! But you gotta wonder why there is such a huge gap between these guys and the real contenders running 2:05 (4:4x pace!) and the like..