Right you are. American aid to the Soviets played a huge part, particularly with trucks.
But consider the Soviet’s home-grown T-34. Cheap to make. Nothing complicated there. Perhaps the T-34 was not as good as the expensive German Panther tank. And it certainly wasn’t as good as the very expensive Tiger tank.
One Tiger against one T-34, it’s no contest. But one Tiger against 20 T-34s and it’s off to Berlin the Soviets go.
The T34 was better than the American M4 Sherman tank by far. Even in WW2 we depended on air power to pick up the slack where we had weaknesses against the Germans.
And quantity and quality are minimally required to some point where the combination has the sweet spot to win in battle.