The USSR acted as a serious meat grinder, but a little less than half of German losses where on the eastern front which also included polish forces and the USSR had minimal impact on the Pacific front.
The US footed a lot of the material costs needed for Europe and the USSR to stay in the fight via lend lease. To the tune of about $575 billion inflation adjusted, and 22% of that going directly to the USSR. https://en.wikipedia.org/wiki/Lend-Lease
So, the USSR played a significant role, but where far less effective than your suggesting.
If you’re thinking of losses as lives in the German army and you include non German forces added to the German army and you assume all deaths on the eastern front where with the USSR then you can get very high numbers for German deaths due to the USSR.
On the other hand if you look at losses as the capacity to make war then things are different. As a land war the German navy for instance was largely uninvolved so you need to consider how many tanks was a battleship worth. How critical was a lost factory or oil field etc. And in that context while Germany gained some men from their invasion of the USSR* a major goal was the acquisition of oil in the caucuses, because having been cut off from other sources they would have likely lost with or without the invasion.
In the end it was the loss of aircraft factories more than aircraft that really cost them the air war. While we think of WWII as a modern war, Germany used 2.75 million horses in WWII. Fuel, raw materials, and industrial capacity for engines where tight.
*~230,000 of the deaths on the eastern front where originally from the USSR but fighting for the Germans.
Just to add, the most extreme version of this was probably the thousands of miles worth of defenses Germany built along the coast which diverted a great deal of men and resources without meaningful associated deaths.
The French resistance was again almost completely useless in terms of killing German soldiers. However, they had a more meaningful impact on German military effectiveness as demonstrated by deployment of forces.
To be clear, I am in no way debating the casualty figures, but winning a war isn’t just about running out of people. Militaries trade off between different types of resources.
> More than 80% of the aid to USSR was delivered after the Battle of Stalingrad was won by the USSR, and the outcome of the war was pretty much settled.
If you think WWII was settled in February of '43 then that says all we need to know regarding your credibility on this matter. I only mean to be as harsh as is necessary, but it is crazy to be as cavalier as you are being regarding the history of a war where so many lives were lost.
The US footed a lot of the material costs needed for Europe and the USSR to stay in the fight via lend lease. To the tune of about $575 billion inflation adjusted, and 22% of that going directly to the USSR. https://en.wikipedia.org/wiki/Lend-Lease
So, the USSR played a significant role, but where far less effective than your suggesting.