Us companies like Facebook and Twitter had a chance to operate in China as long as they were willing to follow local laws/policies; they were banned because they didn’t want to cooperate.
On the other hand, TikTok seems willing to obey us laws and is bringing its team/data center into the us. Banning TikTok in spite of that sounds similar to injecting disinfectant for COVID
China is a communist regime. They can do whatever the hell they want, why would american companies spend any time conforming to their demands when they can pull the rug out from under them at any time. Also, they would be under their total control forever.
Many american companies seem to collaborate successfully with this communist regime including but not limited to Apple, Microsoft, Amazon. Even Google still has Google Ads platform operating in China.
The TikTok app is served by the US data center operated by a team in the US. If they violate any US law, federal regulators can find out and punish TikTok based on evidence like how they fined Facebook. Being owned by the CCP doesn't mean that they cannot obey US law.
And it is really hard to imagine how CCP can harm the interests of the US people with those short fun videos. Does Trump believe virus spreads via these short videos?