This article from 2024 gives a pretty good rundown as to why using this reasoning to ban Tiktok will set a very bad precedent:
If the govt cared about your data privacy, they would create data collection regulations that they could then use to ban tiktok if/when they violate them.
Disclaimer: I am not saying Tiktok is a great app with zero issues. This is a concern about causing long term problems by using a short term easy solution.