If China wants, it can seal off rare earths to all these countries in retaliation and collapse their tech industries immediately.
Look at your delusion here, staring down the fact that China has more advanced telecom technology than anybody but still attempting to retreat to your safe place by imagining a situation where China is still helpless.
"If they want" is as funny a precursor as it gets. Nobody wants to be behind and the US certainly wants to stay ahead of Huawei, so it's a given; there is want. But the last time the US tried the petty route, attempting to cut off chips to stifle competition, it led to China having its own superior supercomputer chips in a year.
So play the cut off game. I really want to see that happen and these companies throw away all their market share in China to have Chinese rivals take it over and surpass them before the employees they have to lay off even get the last of their severance pay.... and then they can cry about trade imbalance haha.