It is a fact that mining power is mostly based in china. And there are so many bitcoin adopters there. But i don't think they totally control the bitcoin. They only have enough impact.
Yeah no doubt China is well developed country and there are so many rich people who can make bitcoin high for investing but still they can not control bitcoin because there are 90 percent countries in the world are bitcoin supporters and they are making bitcoin web stronger and only china can take hold over the growth of bitcoin.
Yes China is huge place for crypto users and there are so many people who daily makes thousands of transactions on daily base but still there are no chances for controlling bitcoin because bitcoin itself is an independent currency that is growing around the world then it seems silly to believe that someone can ever control bitcoin so forget it and keep investing.