Those guys all have power in their hands and they didn't rely on their chins anywhere near the degree that the Diaz bros do. Diaz bros fights are so one-sided early on because they don't have the physical gifts that more powerful, explosive, muscular fighters do. They outlast. Those guys didn't try to outlast you. They tried to take it to you.
Diaz bros have volume instead of power. They always come to finish the fight.
If there weren't time limits Diaz bros would be finishing all of their opponents. Pacing yourself/cardio is the most important part of fighting, more important than technique and more important than power.
Also Wanderlei is the epitome of a fighter relying on his chin. He relied on his chin way more than Nate does for example.