It is very easy to end the conflict, it is just that the only realistic scenario for ending the conflict does not suit either Kyiv or Washington.
I think you're wrong, Putin's death suits Kyiv just fine. Not sure about Washington, he's been dead for a while so probably has no strong opinions about this.
That's just not true there were many articles analyzing successors in case of Putin's sudden demise and majority concluded that successor would be worse off for Ukraine, some military general or Medvedev. But that just doesn't fit into the narrative of Putin being this madman and a single cause of this conflict, so the hopium that Russia would just fold and run away only if Putin dies continues to spread by propagandists.
Now Washington is unambiguously saying that China is aiding the Russian military.It's like they don't want freedom cookies and NATO showing up in their sphere of influence, and are challenging the current world order. But that would mean that Ukraine is just a proxy and collateral damage in this global conflict. I mean yes yes all just one evil madman Putin blah blah blah