In opposition to the recent tightening of ties between the US and China, some US politicians just can't quit hunting TikTok and fear-mongering over it despite the lack of evidence that the platform has been used for nefarious purposes. An FTC investigation is just another example of the US trying to get a leg up on China rather than work with Beijing towards a stable economic global environment.
Public denials of TikTok accessing US user data don't mean much when executives were recorded saying this actually happened. The House bill is one way the US can better protect itself against China weaponizing TikTok, but FTC action is a solid tool to force more transparency from the platform or make it pay a steep price for potential violations of US law.