This is the same logic that people used to support the Putin 4D chess master theory... Something governments can be wrong or make the wrong moves. Russia had all the information it needed on Ukraine and yet completely misread the situation, hell they're mis-reading their own politics, that's why the coup is even a thing.
From what I could tell, China didn't want the Ukraine war. They poured billions into Ukraine before the war, they knew that the geopolitical situation would be heightened after the War, that the West would unite and start rearming again, they would be upsetting their biggest customers, they would have to disengage from Russia or face sanctions. There's nothing to gain for China, even if Russia did take over Ukraine in 3 days. They allowed it anyway, when it's clear that Chinese support for Russia is the only thing that is keeping Russia going for so long. If China had issued an ultimatum, invade Ukraine and we stop trade with you, would Russia have invaded? Probably not. Or over the year long war, another ultimatum "we will stop trade and invade if you don't make peace" or something along those lines could have forced Russia into a ceasefire or peace deal, whether Putin like it or not. China and Russia are not equal partners, China needs to act like a superpower and actually throw it's weight around, not act like it's blameless.
Do you know why superpowers are superpowers? It's not just that they're powerful. It's that the world revolves around them, every war, every policy made by countries, trade deals, coups, everything is done or influenced with a superpower in mind. China is a superpower now. Even the tiniest thing that they do has massive ramifications around the globe, even China staying neutral and buying Russian oil and letting Russia destroying itself is partly China's fault when there's no way Putin would have carried out the invasion if China had been opposed to it, or when China could have easily forced Putin to negotiate a bad peace deal anytime she wanted.
Just look at NK. Do you really think China wants NK to be a failed state that stirs up tension with important trading partners in the region and refuses to developed and sucks up Chinese aid like a black hole? Is it some 40 year long 4D plan by China? No, of course they would rather NK be China's version of SK/Japan, wealthy, developed, able to trade more valuable goods and services and still acts like a Chinese vassal state. And yet even after decades, they fail to open NK up and actually enact polices to make NK more developed. And yes, this failed states shitting the bed is kinda China's fault when it's the main nation enabling them, NK won't exist with Chinese support, Russia won't have started or continued the failing war without China's support and China propping the economy up.
Again, just watch as China does nothing again as Russia just continues to degrade and degrade until you got another dozen nuclear armed rouge states all bordering China.
