>People brainwashed into supporting Russia do not deny the scale of devastation and human tragedy. They just attribute it to the Ukrainian military.
So I completely disagree here, because it's not an either or. You're right that people brainwashed into supporting Russia will, in certain circumstances, accept that the destruction is real but attribute it to Ukraine. And I completely agree with your pessimism.
But the logic of propaganda, and of a brain consumed by propaganda, is a hall of mirrors full of contradictions. Where convenient, and where possible, the scale of destruction will be denied, and where it can't be denied, it will be explained away.
Propaganda can't be defeated by disputing individual one-off statements, the totality of the system of propaganda has to be shown to be so full of contradictions that it takes more effort to sustain than it does to accept the truth.