Ultra high-volume training will probably be looked back at as a gimmick in the next couple years. It seems to work for a select few but for most it only adds fatigue and blunts performance. 40+ hours a week isn't generally sustainable or beneficial for a 9+ hour gravel race.

It seems every niche goes through this, from what I can tell MTB racers tried something similar in the early 2000s and such training is constantly resurfacing for Road racers.