Looking into Norman Stone's book, still virtually alone as the only academic history of this side of the war (Pritt Buttar's written excellent popular histories, though), much of stems to the twofold aspect of logistics and the Rocks, Paper, Scissors trio of Germany-Russia-Austria in descending order. Germany put its major strength into the Western Front but was logistically most flexible of all the Great Powers. The Russian Army fought over a vast front and took enormous losses that left it hemorrhaging manpower to stay in the same place. Austria hemorrhaged manpower more swiftly with less ability to replenish it, and combined with the sheer awe-inspiring distances of the front and the length of individual battlefields, it was impossible for armies to concentrate in depth.

A factor that's neglected is that it wasn't just Germany's war, the Austro-Russian battles were as decisive if not much moreso for the Central Powers as a whole. They left Germany perpetually propping up Austria and limited its abilities to take initiatives (ironically leading Russia to lose the war where German overstretch and failure would have done much more to win it for Russia than it was capable of doing on its own). Germany would ultimately pull off amplifying the Russian Revolution and breaking the Provisional Government and the Soviet of People's Commissars to 'win' and impose Brest-Litovsk. Austria was broken in 1914 and a corpse given the Pope Formosus treatment after 1916. The Central Powers coalition was defeated in 1914, though this did precious little to win the Allies the war.

The Eastern Front shows more of what World War I would be like if it had stayed as mobile as it was in the West in 1914 and 1918. World War I armies, as shown by more modern takes that integrate in the Central Powers experiences like those of Asprey and Herwig, were an unenviable combination of colossal and able to take and deal out a beating and lacking the command, control, co-ordination, and communication elements to make swift decisions and carry them out in time to get the kind of decisive battles in the Napoleonic and WWII eras. Didn't matter what society spawned the armies, or who commanded them past a point. There was a sliding scale of inefficiency and brutality.