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.
