What must be worrying China is that Russia, whose weapons are the basis of a fair amount of China's equipment is suffering huge losses in people and equipment. Are basically being hammered by equipment that is often second line. Leopard 2, Challenger and even M1's (when they arrive) are all to be replaced in the near future. Storm Shadows which were purchased decades ago and are in a lot of cases being used by Ukraine as they are reaching the end of their shelf life and would have to be destroyed anyway. The same applies to the M1 Bradley and a lot of the Artillery both towed and self propelled is out of date. Starstreak AA missiles were out of production and the Gepard AA tanks were replaced my more modern equipment in NATO army's.
There are of course exceptions to this but it does apply to a lot of the kit Ukraine have been given.