Yeeeeaah, I really can't see that happening. Ukraine has a much smaller economy, a much smaller pool of conscripts, and less foreign assistance. Ukraine gets more free money and supplies from other countries but Russia is actually getting shock troops from North Korea and that's what Ukraine needs more than anything to win a war of attrition against a significantly larger country.

Putin is an asshole, he doesn't care about sanctions and tbh I'm not confident the Russian people do either. Europe, despite their harsh rhetoric, is still addicted to Russian exports, and their hypocrisy is so bad that there are actually Russian pipelines in Ukrainian territory which the Ukrainians are afraid to sabotage because they don't want to piss off the people who are funding their war.

Maybe if Prigozhin didn't get cold feet during his coup attempt it could have ended the way you describe but I don't think that's the sort of thing that anybody can count on happening again.