That's historically true - Germany was no match for the Soviet Union. The question has always been asked "what if" Germany did conquer Moscow in Operation Barborosa?
https://www.historynet.com/what-if-the-germans-had-captured-moscow-in-1941.htm"But would the fall of Moscow have meant the defeat of the Soviet Union? Almost certainly not. In 1941 the Soviet Union endured the capture of numerous major cities, a huge percentage of crucial raw materials, and the loss of four million troops. Yet it still continued to fight. It had a vast and growing industrial base east of the Ural Mountains, well out of reach of German forces. And in Joseph Stalin it had one of the most ruthless leaders in world history—a man utterly unlikely to throw in the towel because of the loss of any city, no matter how prestigious."
"A scenario involving Moscow’s fall also ignores the arrival of 18 divisions of troops from Siberia—fresh, well-trained, and equipped for winter fighting. They had been guarding against a possible Japanese invasion, but a Soviet spy reliably informed Stalin that Japan would turn southward, toward the Dutch East Indies and the Philippines, thereby freeing them to come to the Moscow front. Historically, the arrival of these troops took the Germans by surprise, and an unexpected Soviet counteroffensive in early December 1941 produced a major military crisis. Surprised and disturbed, Hitler’s field commanders urged a temporary retreat in order to consolidate the German defenses. But Hitler refused, instead ordering that German troops continue to hold their ground. Historically they managed to do so. However, with German forces extended as far as Moscow and pinned to the city’s defense, this probably would not have been possible. Ironically, for the Germans, the seeming triumph of Moscow’s capture might well have brought early disaster."
In fact, Germany was ill-prepared to start a world-war. General Ludwig Beck, who was Chief of the German General Staff in 1938, felt that Germany needed more time to rearm before starting such a war. In his assessment, the earliest date Germany could risk a war was 1940, and any war started in 1938 would be a "premature war" that Germany would lose.
Of course, Hitler didn't listen and fired Beck, who was later involved and implicated in the assassination attempt on Hitler in 1944 (Operation Valkyrie). He was arrested and allowed to shoot himself to avoid torture by the Gestapo.