You're not understand how's Bitcoin work, even if Bitcoin miners were mostly operated in China, it doesn't make China can control Bitcoin including Satoshi. If Satoshi implemented to change Bitcoin protocol from Proof Of Stake to Proof Of Work, it needs at least 51% Bitcoin's core team need to agree with that's suggestion. But since most people always consider the decentralization is the most important thing in Bitcoin, such kind change is impossible will happen.
Any change in the protocol, soft fork or hard fork, must be done by community vote from people who own hash rate on Bitcoin network. Therefore, it is impossible for a single person, miner, mining farm to change the protocol to a better or worse new protocol.
Community has their voice and power so that they will look forward to upgrade the Protocol to make it better for everyone engage with it. This community decentralized power eliminates risk for bad exploitation in Bitcoin protocol to change it for benefit of minority.
Changing Bitcoin algorithm from Proof of Work to Proof of Stake is impossible. No Bitcoiners will support it because it will create risk of centralization from which something worse can happen. We saw many problems with centralized Proof of Stake networks.
