I like to put it like this, when it comes to the Eastern Front.

Operation Barbarossa destroyed the Heer's ability to conduct multi-front strategic offensives. You could say it ended at Moscow in december 1941.

Operation Blau (that concluded with Stalingrad and the evacuation of the Caucasus) destroyed the Heer's ability to condict a single-front strategic offensive.

Operation Zitadelle (Kursk) and the following Soviet counter-offensive destroyed the Heer's ability to conduct an operational offensive.

Operation Bagration (the Soviet summer offensive of 1944) destroyed the Heer's ability to conduct a strategic defence.

Seelow heights destroyed the Heer's ability to conduct an operational defence.

With the leadership of Germany focused on grand offensives, dramatic last stand defences, great gambles and not a step back type of warfare, the Germans had no chance to gain any kind oof favourable peace after Stalingrad, but it was Operation Bagration that broke the back of the Heer. Before that they were still causing more casualties than they were suffering and with a different leadership and focusing on flexible defence, mobile warfare and bleeding their enemies white might have had a chance to fight the Soviets to a standstill.

So I get the impression that most people seem to view Stalingrad as the decisive battle in WW2 as it had a major impact on Germany and the USSR. But were battles such as Moscow and Kursk equally, less, or more important?

Stalingrad was only a turning point in perception of the war. If there is a turning point of the war it will lie somewhere in 1941, maybe Moscow maybe before that. While Stalingrad showed the World what was to come the overall outcome of the war was already set and therefore Stalingrad is no real turning point of war its not even more crucial than all the over major operations. After the failed Barbarossa operation the Eastern Front was a war of attrition which was favouring the Red Army.

The Wehrmacht lost 400.000 man around Stalingrad over nearly half a year. They lost 200.000 in 6 weeks at Kursk.

Obviously describing Stalingrad as the turning point will help with book sales since every battle as to be attributed with a unique feature. The damage inflicted on the Red Army was still significant showing that in a war of attrition Stalingrad wasn't even that unique. A big part of Axis losses were Allied troops whose combat value was lower anyways for a variety of reasons. Italy dropped out of the war half a year later anyways. If the outcome of the battle was different the balance of power would have been nearly the same. Obviously the Red Army would be worse off but still.

Ironically the next "decisive" battle shows that. The Battle of Kursk. The Wehrmacht inflicted huge losses on the Red Army during the attack and during the defense but that didn't madder. The Red Army sustained 4 times the losses of the Wehrmacht during this battle but still came out ahead. This shows that the narrative of "turning points and decisive battles is" is completely wrong. Those huge battles only accelerated the attrition and as the Kursk example shows a 4:1 attrition rate was still fine for the Red Army. How can losing some more men at Stalingrad change that? It can't. The Blau operation was inteneded to secure oil but even that wouldn't have changed what was described above. The Wehrmacht was not in reach to capture anything valuable and therefore the only way was to grind the Red Army down and that was a lost cause. A success at Stalingrad quite likely would had other negative impacts on the Wehrmacht. The front would have been considerable longer and a longer front favors the attacker and the Army with more ressources. The defender has to spread his mobile reservers thin while the attacker can choose any point to attack.

War of attrition reads more "boring" and reducing all Battles to "kill ratios" feels weird to most casual readers. But thats what the Eastern Front was in the end. Every planned Operation was in the end intended to inflict the maximum casualties. While even in the supreme commands of both armies there was a misconception regarding that. In 1943 both Armies were not in reach of anything vital. Every operation was trying to capture some meaningless land.

Kursk describes that perfectly. The entire plan of Zitadelle was to make a pincer movement on Kursk to capture a large part of the Red Army. Why Kursk ? Would the capture of Kursk change anything? No.

Again Kursk was a turning point in perception. The Wehrmacht now wasn't even able to launch an offensive which would break through.

Is it really necessary to attack Kursk, and indeed in the east this year at all? Do you think anyone even knows where Kursk is? The entire world doesn't care if we capture Kursk or not. What is the reason that is forcing us to attack this year on Kursk, or even more, on the Eastern Front? Guderian

This highlights that even people like Guderian not really got it. There was nothing in reach for the Wehrmacht. The destruction of the Red Army was the war aim not some meaningless city. Obviously if you are on the losing side in terms of attrition and production you are indeed forced to attack unless the enemy does. Mannstein here seems to be wiser, his plan was to move slowly backwords and maximise the casualties inflicted. Counter attack from time to time and take what is offered but not more.