China controls over 50% of the btc hashrate meaning they can do a 51% attack on the bitcoin network or control which btc transactions are valid according to their liking correct?
I believe a bulk of the mining hashrate is as a result of mining pools; miners from all over the world concentrate their computing power to a single server to increase the chances of them getting the next block collectively. This does not mean the hashrate is controlled by China, miners can easily switch to pools from other nations.
Indeed, there is no monopoly from China on the hashrate of BTC. Since the ban, the bulk of mining to maintain the network coming out of China is somewhat something of the past, as miners have already started to relocate.
As for China manipulating BTC's consensus, well, that's not so easily achieved because despite the miners having been in China it doesn't mean miners knew exactly where each were located to forum such an organised attack. Plus, the penalties if found out are harsh and it would destroy any miner's equipment and trust for future mining participation, a risk not many are prepared to take.