But Ukraine can't give up
Sure it can. It seems you folks only read military-related news from Ukraine, but ignore completely the developments taking place in civilian life. Discontent is brewing in Ukraine, and as winter approaches it will only get worse. People there are not blind, and they see that the West gives just enough weapons to allow them to hold their ground, but not enough for them to win. On news websites, under relevant articles, comments like "these guys want to fight Russia to the last Ukrainian" proliferate (today I saw a bunch of these comments under an article about how the US said it will take some YEARS before Western jet fighters can be transferred to Ukraine) . Sometimes, you even see posts along the lines of, "we'll give up to the Russians, and then see how these two-faced kurvas will feel about not helping us when we needed it".
People are pissed at Zelensky, for things like doing a glamorous Vogue shoot, or engaging in petty political games while a war is raging. Recently he revoked the citizenship of certain political opponents (ostensibly for violating Ukraine's dual citizenship law), barring their return to Ukraine from trips abroad where they had travelled to drum up more aid. People are sick and tired of the so-called national TV marathon, where all the channels in Ukraine have been broadcasting for the past few months the same stream produced in Kiev (suspiciously featuring only pro-Zelensky voices).
The biggest problem, of course, is that Zelensky has not changed the laws forbidding men to leave the country. If these masses of mostly unemployed men were irate three months ago, now they are blistering mad. Many haven't seen their wives and children in half a year. A recent initiative by the government to allow men to leave the country starting Sept. 1 for periods of up to 7 days, in exchange for posting a 200K Hrivnya collateral has caused unanimous disgust. It's clear it favors wealthier people, and that very likely most of them will not return. In brief, things in Ukraine are approaching a boiling point. If they do not sit down for negotiations, then there is a very real chance there will be a military coup.
While he's lauded as the "Churchill of our times" in the west, he's becoming an increasingly unpopular figure at home.