PoW was due to energy waste. Also China’s reason for banning Bitcoin has nothing to do with protecting the environment from harm. They should actually focus on the proper supply of energy.
It is not about energy consumption but the revenue. Government want to tax. Since they cannot able to control it, they rather choose to ban bitcoin. Even if several countries like (China, EU etc.) should merge it is practically impossible to stop, because bitcoin is now too big.Let the government do what they want, but it would not stop people from using bitcoin.