Turchin offers a model and shows the data being used as input to the model. These may be disputed, but it’s a theoretical framework and documented assumptions.
What do you offer?
Turchin’s model boils down to Russia has more people therefore it can sustain astronomical losses and will win a war of attrition which explains perfectly Russia’s victories in WWI, the Russo Japanese War and Afghanistan…oh wait never mind or as my Mom would say, a simple mind is a blessing.
Russia will run out of ammo, artillery tubes, and the courage in the bottom of a vodka bottle before Ukraine runs out of bombs, planes, tanks, or manpower not to mention the political will to carry on. There has already been at least one attempted coup.