There is no win-win way out of this war
The basic thesis regarding the Russo-Ukrainian war, which Western politicians and most experts do not recognize – because it is scary – is that there is no win-win way out of this war.
In other words, there is no win for Russia that would not be a loss for Ukraine at the same time, and vice versa.
For the same reason, the "both sides lost" scenario is also impossible, because every loss of Ukraine is automatically a win for Russia.
However, it is possible to manipulate here by lowering the bar for Ukraine: say, it won because Russia did not achieve all its goals in this war. This is regularly heard.
The wolves ate the sheep, but not all; therefore, both the wolves are relatively full and the sheep are relatively intact. You can try to sell it as a win-win, but it doesn't work out very well (and it suspiciously resembles the Russian classic: "Be grateful that you are still alive").
And if we discard this manipulation and evaluate the win/loss from the starting position before the start of the full-scale war, in fact there are only two ways out here: either Russia will lose, or Ukraine will lose.
But Russia's loss is the immediate end of Putin's rule and, quite likely, of the Kremlin's; therefore, Putin will actually fight until he dies or until everything in Russia begins to fall apart so much that war would be the least of his worries. (This is also a thesis that many people are afraid to admit, so it's better "not to look up".)
And it is still not possible to incline Ukraine to a partial loss, which will be presented as a partial win.
Therefore, again and again, the efforts of the Western political community are aimed at solving an intractable problem: how to make Putin "himself recognize" the irrationality (what?!) of a further war and agree to stop it under some conditions.
Although, in fact, this intractable problem is only a screen that covers the fear of the real problem: which side in this war should lose, so that this loss minimizes the current and future risks for the West.