Germany ran out of fuel and weapons. Every time an allied tank was destroyed it could be replaced. Every time Germany lost a tank in action, it was either not replaced or not as easily replaced. Yes both the Panther and the Tiger were better tanks than the Sherman, but the allies could continually keep putting more and more tanks etc into the battle. Also Germany ran out of fuel to keep their armies moving. During the North Africa campaign, Germany used up tons of fuel just getting fuel to the front line. The same thing happened on the Eastern front
Also the japs betrayed their German allies by signing a peace treaty with the soviet union which allowed the soviets to move their far eastern armies to the front against Germany. Never trust a gook.