China is maybe controlling bitcoin mining, but I don't think it controls bitcoin itself.
Yes, China has more than 51% hashrate, because some people use free power, they steal electricity, very sick miners.
Do you have proof that China is a country that controls mining in the bitcoin..? . If you do not have proof then thinking positive and remain calm, do not let it harm to yourself. Indeed China into a country that has the highest percentage compared to other countries, but that does not mean China can master or control it all