The point was, that the entire eastern campaign, designed by Hitler had a worthful purpose, not that it was a lunatic attempt to wipe out bolshevism as said by stupid german generals after the war, building uppon their memoires (btw incompetent german generals who surrendernd to the west). Paulus himself was against striking eastern at first because HE WAS a competant logistic master and saw that it was a madmans plan to fall into the UdssR in closed front, more then 800km . If the gernerals would have followed the ground points of the eastern campaign accordingly to Hitlers goals, the eastern gamble would have paid of IMO. NOT TO SAY THAT THAT WOULD BE A GOOD THING. Point is, german high command were morons, Hitlers points to attack Russia were right.
There was no other way to produce enough Airplanes, U-Boots and Tanks with the ressources germany had by the middle of 1941, to end Britian and the Allies. And after the USA joined the War in late 41, getting the Oil was a thing of survival against allied superioty.
So if generals would have just defended northern and centre russian front after Nov 41 and focused striking south as Hilter later did when he take over command (too late tho) Operation Barberossa would have paid of and would at least delayed Germanys defeat to the late 40s.
Still Probs to those poor men fighting at Stalingrad for both sides, surely the battlefield closest to hell in the 1940s