Without a doubt, a major part of the 2 minute lower WR today in the women's marathon is the shoes. The Adidas are 2 ounces lighter than the Vaporflys and that weight difference, assuming all else equal, is worth about 1 minute, according to formulas from several different studies.
Seems like the shoe wars just escalated again.
Depending on your views, this:
a. Creates new excitement, records, etc
b. Further erodes the integrity of the sport's records
c. Drives up the cost of the sport, making it less egalitarian
d. Fattens the bottom lines of Adidas and Nike
e. Is the inevitable progress of technology
f. Some or all of the above.