Hi,
China has already banned ICOs and is shutting down Bitcoin exchanges. What would happen if they also banned crypto mining?
Then there would be a large portion of hashing power removed from the pool and there would need to be a large investment into the same hardware to make up for it, provided that the hardware is not moved out of China and then used again to continue mining cryptos. China banning crypto mining is relatively unlikely in most circumstances, but it is entirely possible that they would seek to do something along those lines if the miners are not paying the government properly.
The difficulty would also decrease somewhat significantly, resulting in new miners having a chance at getting into the scene and starting their own operations.