I'm not ignoring the points about Russian weakness, I'm dismissing them. We've been hearing the "Russia is on the verge of collapse" narrative for years. I think it's wishful thinking and refusing to engage the thought of negotiating because of a vacuous Hitler narrative is just prolonging the conflict. When something doesn't work for years one looks for alternatives.
Here's an article about how economic stagnation doesn't necessarily mean military defeat with authoritarian regimes.
I'm not trying to disprove anything, just showing that counterpoints are available. Ultimately we have no idea about when Putin will decide to stop, or whether he will at all, and we don't know how the economic implications will affect Russia's warfighting ability because we can't apply a democratic model to it. All we have is years of liberal optimists being wrong and a million dead.
The point of the cartoon is to show that negotiating is bad and I think that makes no sense unless you're a capitalist arms manufacturer or an imperial revanchist.