You missing an important point here, compliance with local laws. US companies CAN do business in China, only if they comply with Chinese laws. Whether these laws are just or unjust is beyond discussion of this thread, what matters is if you want to business in China, you have comply to it.

Imagine, if a Chinese company wants to operate in US but refuse to comply local regulations, what will happen to that company?

Fb, Google and others are banned from China because they refuse to cooperate. What about Tiktok?