That is a very curious reading of history not shared by the majority of military historians in either the West or East.
For example, according to the US military (See The West Point Military History of the Second World War which is available on Kindle), without US support, WW2 would have lasted 1-2 years longer but the Soviets could have defeated Germany all on their own, both without lend/lease and also without any US involvement at all in the war on Europe. Here is what the West Point history says at the start of their section on Lend/Lease:
"Although nearly half the population and the great industrial regions of the Donets remained under German occupation, the Soviets still found men for new armies and vastly increased war production. They defeated the Germans at Stalingrad almost entirely through their own efforts and would probably have won the same victory if they received no assistance at all."
Or you can read When Titans Clashed by noted British historian David Glantz, which reads
"If the Western Allies had not provided equipment and invaded Northwest Europe, Stalin and his commanders would have taken twelve to eighteen months to finish off the Wehrmacht. The results would probably have been the same, except that Soviet soldiers would have waded at France's Atlantic beaches rather than meeting the Allies at the Elbe".
It is sad that many in the West don't know that 80% of German war deaths were at the hands of Soviet soldiers.
The reason why historians believe this is because of the timing. The vast majority of Lend/Lease aid was delivered in 1945. Only 20% of aid was delivered before 1944 to the Soviets, but by that time the tide had already turned (Stalingrad, recognized as the turning point, was in winter of 1942 to the start of 1943). By the time Lend/Lease really took off, the Soviet army was already vastly larger and more capable than the German army, which was in full retreat. During the dark days of 1941 and 1942, Lend/Lease was miniscule, primarily consisting of things like cans of spam and beans. The Soviets derisively called Spam "The Second Front", because instead of delivering the promised second front, they received cans of spam in small quantities during the darkest period of the war for the Russians in 1941-1942.
The massive factories and military gear were sent after the Germans were retreating, and therefore most historians believe they had the effect of speeding up the collapse of the German forces, which was the main effect of the Normandy invasion as well.