Also it has been allowed to operate for years till now, What sudden change of circumstance has occurred that banning it is imperative now? The government has not made any explanation.
Ideal solution in this case would be to define a data security and privacy legislation through Congress applicable to all social networking apps/services and clarify the terms under which they can operate. Then if TikTok is complying with them they can operate and if they are in violation they face necessary consequences.
Instead what is happening is arbitrary misuse of executive/administrative powers to promulgate a ban without due process, and based merely on fear and speculation.