Why are MMA fans allergic to analyzing the Khamzat-Usman fight correctly?

Maybe an abrasive title but this is a pet peeve of mine and I wanna know where or how I’ve erred.

The common interpretation of this fight seems to be that Khamzat was lucky to face Usman in a 3-round fight and that it exposed flaws in his cardio.

The only way this holds up is if you think Khamzat is lying about his hand injury.

Otherwise, it makes no sense. As I see it, he was backpacking Usman quite comfortably. His activity at pretty much the exact moment he messed up his hand, which was an unintended consequence of an Usman last-ditch maneuver to avoid getting finished.

How is it not obvious that Khamzat’s hand-break rather than poor cardio was the causal link here? What am I missing?

He was way more active in the third round of the Burns fight than the second or third rounds of the Usman fight…why would he get more tired doing a thing he’s a natural at (wrestling) than trading shots with Burns at a weight division he had a harder time making weight in?

How was the injury NOT the clear swing-factor as opposed to Usman’s rust or Khamzat’s shitty gas tank?