The comment I originally replied to likened tiktok to a printing press, but that's not quite right.
Imagine a printing press owned by an enemy that would subtly manipulate the text of whatever you tried to print. Or maybe it would omit entire articles from certain recipients of the newspaper, or reorganize the page layout to emphasize different things than the editor intended.
We wouldn't allow this hypothetical printing press controlled by a hostile foreign government to be sold in the US, we would be crazy to.
The US is widely against even having its own government own communication platforms.
So if you want to make the same argument, you will have to declare china's CCP to be a terrorist organization - and all of the legal implications that entails.