"bodybuilding is not an endurance contest!" -Mike Mentzer
I don't think training with volume is pure endurance like a long distance runner or biker. It's still lifting weights. The muscles of a bodybuilder is the result of muscular endurance training. If it wasn't Olympic lifters and power lifters would have the biggest thighs from their insane intensity.
Speaking of big thighs have you seen the thighs of bike sprint competitors? Huge from racing around a track doing a lot of reps spinning the crank.
Remember a lot of volume trainers beat Mike in a lot of contests. He didn't come in second in the 1980 Olympia he came in 5th. Even Viator at his best was training with volume for the London Olympia. Mentzer still has the most influence on my training over my life but I cannot discount other forms of training.
I don't want to get into a volume vs HIT debate. The facts stand that the over whelming amount of champs trained with volume and not hit. One of the ways Jones used to promote the sales of his Nautilus machine was to find a champion bodybuilder who used volume then promote them as the result of one set of 12 Nautilus machines.
I trained with high intensity for decades. I have many of the issues that Arthur Jones wrote in Ironman magazine back in the early 70's I believe when few if any bodybuilders knew who he was. He use to have an animal program that was semi popular on tv. I was really into what Jones and Mentzer had to say. In the early 80's when everyone was doing volume in the gym I was copying Mentzer's workouts. Complete with pre exhaust. I still have what I think is the most complete collection of everything Mentzer wrote in the magazines.