A good victory against the Russians in Ukraine will certainly calm a lot of war ardor on the part of the dictatorships of the planet. At least for a few years.
You see the world getting divided more and more, and you expect that a -penible- victory of a country supported by the whole West would calm down anything? Boomers really are optimistic, or delusional...
For sure it will have different impact than if Russians would won after week of invasion, like many expected. And yes, "west" supports Ukraine, but all this support and weapon wasn't there when war began. I see nothing bad in being optimistic when some good arguments stays behind it.
Just imagine fast victory of Russians, and imagine defeat, when they will have to spend many years to regain military capabilities.
Yes it would have had a different impact. surely the US would calm down with the shit they are doing, and opposidely, Russia, China, or Iran would get bolder. Nevertheless, China and some other countries are getting bolder with this war because they see that they can do more or less whatever they want and that there is now a second "alliance" that is forming on a global scale; against the "West".
On the other side, if Russia is getting exhausted fromt he war, the "West" also pays a lot for it. Notably in energy ((we still get Russian gas, thanks to Chineses and Indians that are tampering/cheating with the origin of gas); by sending weapons that we pay for (and that will end on the illegal market, feeding terrorists that we have in the west especially again) or making ourselves unable to export as much as in the past, but also by the need to maintain a good cohesion between our states, which, as we see, is already hard in normal times, especially when some countries want to take this oportunityy to get more power and weapon, like Germany.
More than for Russia, it would be in our best interest if the war stopped as soon as possible...