A lot of the discussion talks about how China can just develop it's own. But there's more to it. Development isn't free. China has to expend lots of resources, resources that can't be used somewhere else. Maintaining a chip making sector comes with challenges and it's not clear whether China can maintain it competitively through the long haul without paying an outsized price.
Some people think that the US could have cut off China if and when they used the technology to wage war, thereby being "more strategic" about it. But that to can be a dangerous game, and that strategy might not accomplish what it's intended to accomplish.