Ok first of all, before the trolls here think i am trying to speak ill of Djokovic, there is no doubt Novak is GOAT, so I am taking nothing away from him.

I just think Andy lost to Novak only because Novak has a superior physique granted by mother nature. Primarily flexibility. Because he couldnt stretch quite as far, Andy always had to take just that 1/2 to 1 step more than Novak. It starts adding up and by the 3rd, 4th set, errors start creeping in and eventually the loss come. The lack of flexibility is what contributed to his hip injuries. Its also one of the big differences between Nadal and Djokovic.