Y'all are not gonna like this but I think it's in China's best interests to keep their allies like Russia and Iran fighting for as long as possible rather than joining and help win the war and they definitely recognize this. Non intervention has a big benefit of being to supply people with weapons and materials for a long amount of time. Essentially the same method that US took to become a superpower after WWII
Until their borders and sovereignty are threatened again like the Korean War, they'll never join any war in any real capacity other than trading more and making cash
That's the price of ethereum lol