By the material benchmarks sketched above, the war is a disaster for Russia. The value of its territorial acquisitions is low, probably negative, given the devastating nature of these spaces due to Russian shelling and the ensuing political-economic limbo they will fall into as unrecognized conquests. These realities would counsel Russia to stop the war, and there seems to be some dissent in the Kremlin around these points.
But Putin marches on, suggesting that the war is not about any particular valuable conquest anymore, but victory for its own sake. This is an awful reason to fight a war. Ignoring the material balance of costs in pursuit of a victory for prestige is a proven means of sliding into an unwinnable quagmire. This is quite close to the logic of the US in the later stages of the Vietnam War.
In that conflict, much of the US national security establishment recognized that the war could not be won at reasonable cost – without, for example, invading North Vietnam or nuking it. Henry Kissinger apparently felt this way as early as 1966. Yet President Lyndon Johnson did not want to be the first American president to lose a war, and his successor, President Richard Nixon, wanted an elusive ‘peace with honor.’ American credibility was at stake.