That does not mean anything many battles have been won but the war was lost. History has a many examples, Russia has no chance in the long run to win, even if the land is taken it will be given back, or Russia will be isolated from the world.
I think that's not true
if Russia succeeds in subjugating Ukraine within the next decade or two. Russia might then be isolated from NATO countries, but there are a lot of countries that aren't in NATO and that want to buy what Russia sells. Russia is primarily an oil and gas company nowadays. If Russia succeeds in subjugating Ukraine, Russia will probably become an industrial agriculture business too. Oil, gas and food will usually trump political concerns, especially when those councerns are about countries unconnected (in either geographical, social or political terms) to your own and there's no threat to your own. India, for example. It's not under threat from Russia and it's not connected to Ukraine in any way. It's government will hedge a bit while the invasion is in progress, but will continue to buy oil and gas from Russia even then. Or China, whose government doesn't even pretend to care. Two massive countries that account for more than a third of the world (in terms of population) and that will buy what Russia's selling. That's very far from being "isolated from the world". They might hedge a bit in public for the benefit of their own businesses selling to NATO countries, especially their own agriculture businesses (which would then be in a much better position for selling to NATO countries, with Ukraine being removed) but they'll buy what Russia sells.
Isolated politically? Why would the Russian government care? They're running a business. It doesn't have to be popular, just profitable. Besides, it's highly unlikely that Russia will be expelled from the UN or even lose any of its power there. So some countries it doesn't sell things to won't publically speak to it. So what?
I don't think it's entirely a coincidence that the parts of Ukraine Russia is most interested in conquering are the parts with the most oil and gas.
Russia is primarily an oil and gas company. The market for those products is declining (especially in Europe, currently by far Russia's best market) and Russia as it is would decline with it. So it makes sense (in an amoral way) for Russia to steal as much as possible now, while it still has enough money to do so, and use it to make Russia viable as a country without being primarily an oil and gas company. Stealing Ukraine's vast amount of excellent arable land would be part of that, as is stealing as much tech as possible from other countries. Even if Russia currently isn't capable of manufacturing that tech, the knowledge of how to do so is still very valuable. Sure, it might mean that Russian businesses in 2040 are using 2020 tech rather than 2040 tech, but that would be much better for them than using their own 1970s tech in 2040.