I'm going to ask an intentionally stupid question. TikTok is largely just kids dancing and other innocuous videos, even if Bytedance is sucking up all that data and sending it back to the CCP, how does that constitute a national security threat?
I use it myself and never get dancing videos. I get videos about gaming, sketch-comedy, abstract comedy, fails and mishaps, podcast snippets, global conflicts, politics etc.
There's something for anyone on TikTok. It's a bit scary how well the algo knows my interests, but at least it's interesting content.