China has much more to gain by grabbing the resources of Eastern Russia/Siberia.
Russia would nuke them. At least a little.
But Russia is in no position to counter a significant conventional move against them in the East.
Agreed tops is water, largest fresh water lake in the world is in that region. North China is basically a desert very dry
China tried to sneak some pipelines but was stopped by Russia.
Irony is that China can use the same arguments Russia is using on Ukraine, historical ownership…