Why did the Soviet army, which was simply vulnerable at the beginning of the Soviet-German war, always magically reverse in the end?

On the Eastern Front during World War II, Germany began to invade the Soviet Union. At that time, the Soviet Union was not ready to go to war with the Germans at all, which led to the collapse of the Soviet Union at the beginning of the war. Even vulnerable. However, after going through big waves and scouring sand, the Soviet army gained a firm foothold and began to fight back against the Germans. In the end, the Germans were defeated by the Soviets and occupied Berlin by the Soviets. The reason why the Soviet army can magically counterattack is actually very simple. First of all, after the big waves washed sand, the number of veterans with war experience in the Soviet army began to increase. Secondly, the Soviet Union finally completed the relocation of the arsenal and carried out large-scale arms production in the rear. Finally, the Soviet Union's defense was deep, which eventually led to the Soviet Union winning the war of attrition between the two sides in the later period of the war.

First of all, after the big waves washed sand, the number of veterans with war experience in the Soviet army began to increase. After all, at the beginning of the Soviet-German War, the Soviet Union had just experienced the turmoil of domestic political movements, a large number of troops were recruited, and the commander's command ability also had problems. With the progress of the war, although the Soviet army experienced a painful defeat, the combat experience of commanders and soldiers in the army increased very rapidly. These veterans and officers finally helped the Soviets win the final victory.

Secondly, the Soviet Union finally completed the relocation of the arsenal and carried out large-scale arms production in the rear. You know, in the Soviet-German battlefield, the two sides are mainly engaged in a large-scale war of attrition, and whoever has more resources will win.

Finally, the Soviet Union's defense was deep, which eventually led to the Soviet Union winning the war of attrition between the two sides in the later period of the war. The war of attrition is a test of a country's comprehensive strength. Although the Soviet Union and Germany are basically equal in industrial output value, the Soviet Union has more resources and does not need to fight on two fronts, so it finally won the war with Germany.