War is never a good idea for conflicting countries, dialogue is always the best means for actualizing lasting peace between two nations that are in disagreement.
When there is war, the manufacturers of weapons benefit more, because they see it as an opportunity to either sell their weapons or test-run their new weapons in other to know the actual capacity and function of such weapons, in case of future use.
Mercenaries also benefit, as the case may be, either of these countries hires their services in the end they get paid for it, it doesn't matter if they will win or not, whichever way they will get their payment because of the existing agreement.
Note there might be a winner, but the question is, the nation we perceived as the winner was there no casualties recorded by them?
To me, when there is a war between two countries, I don't see any victory of any kind, because in most cases both countries record high casualties and infrastructural damage. Rebuilding and rehabilitating this country involved, takes a lot of time, in some cases, there may not be rebuilding and even though there is, are they going to rebuild the dead ones, the answer is no.
Say no to war, dialogue remains the best option for the resolution of conflict.
As a resident of Ukraine who has directly experienced everything since 2014, I will say one thing: when a crazy, inhibited, homicidal maniac aims to rob and kill you, and has prepared everything necessary for this, plus a bunch of stupid and embittered executors - to "talk" is only to prolong the agony. History knows one rule - if the aggressor is not resisted and destroyed, you will lose. Ukraine has no other option but to WIN. I hope the world has also realized that it has no options to live in peace as long as there is such a terrorist entity on the planet earth, and it must be defeated and destroyed.
I will also bring such an interesting historical observation - as soon as the USSR/Russia had real difficulties and they slipped into another bottom, the number of terrorist, active, groups, and all kinds of terrorist events - fell sharply ALL OVER THE WORLD! In this statistics you can easily see for yourself.
And I hope the cause and effect are quite clear ?
The USSR was given a chance and saved in the second world war. In the hope that the USSR would become an adequate world leader. But they were wrong... Even earlier the USSR and Muscovy were saved from starvation and riots by the West...Hoping that the USSR/Moscow would be adequate partners...They were wrong. I don't think the world wants to be wrong again.
Speaking of benefits. There is one quite proven and logical, economic "justification" for a terrorist country to attack Ukraine. In 2006-2012, the largest shale gas deposits in Europe were discovered and explored on the territory of Lugansk and Donetsk regions ! If you search history, you will be surprised that from about 2008-2010, the Kremlin started pouring huge amounts of money into the propaganda "shale gas is an earth killer". Although, if you go deeper into the issue, you will also find out that Russia produces a lot of hydrocarbons using this technology, and no problems
After the propaganda failed and Western production companies actually came to the finish line, to sign contracts for the beginning of production, came 2013/2014. As you will notice, it is the areas where the main shale gas deposits are located that are temporarily occupied by Russia. And here the "economic benefit of Russia" in this war is quite clear - to prevent Ukraine from producing and selling gas to the EU, especially since Ukraine has a well-developed gas network (gas pipelines, storage facilities), while Russia does not have it and moreover would get a competitor.
But now all the "benefit of russia" has turned into the collapse of the economy, impoverishment of the population, and the status of a pariah country