The very fact that not a single western social network is permitted to operate in China is a sufficient reason to ban TikTok in America.
Instead, there are substantial arguments about freedom of speech and accountability. Even though they are messy, they are what we need to apply here because they are a legally binding framework that we built over decades.
By the way, I found Levitski and Ziblatt's book "How Democracies Die" [1] a pretty good treatment of these issues of balancing freedom of expression and democratic resilience.