The article is not as unrealistic as that, the author does point out that Putin is not just looking at the state of Russia, he’s also looking at the relative state of Ukraine and its support from the West.
The death zone isn’t the point at which they die, it’s the point at which they are consuming their own long term strength and capacity to recover in order to sustain their effort .
To our utter shame, we have never actually committed to Ukrainian victory or Russian defeat, but merely to tenuous Ukrainian survival. I firmly believe this war would already be over, or effectively so, if Ukraine’s allies had spent what we have up till now in the first 2 years. Even from a cynical financial point of view it would have been the better policy.
I don't think doubling the support would have been nearly enough to ensure Ukrainian victory.
The fundamental issue is that Russia has not fully committed to winning the war either. While losing the war would be an existential threat to the Putin regime, not winning it is not. As long as the war drags on, there are more effective uses for Russian resources to ensure the stability of the regime. But if the war becomes an existential threat, Russia could mobilize its entire economy.
A regime change in Russia is the only way Ukraine could win the war. Maybe by a coup or by military force. Or maybe by an arrangement, where the current regime can retire comfortably in a third country without having to answer for its crimes.