Tiktok has some serious problems with censorship. It's been absolutely proven that Tiktok censors content that the Chinese government dislikes. Even if Tiktok/Bytedance insists that they aren't owned by the Chinese government, they are owned by Chinese entities, which subjects them to Chinese government censorship, and may require them to deny that censorship.
The study: https://networkcontagion.us/wp-content/uploads/A-Tik-Tok-ing-Timebomb_12.21.23.pdf
Article about the study: https://www.nytimes.com/2023/12/21/business/tiktok-china.html
Antipaywall link to that article: https://archive.ph/MLATC
I don't disagree that Facebook, Youtube, and Twitter have their own set of things they censor. I don't disagree that Tiktok is being singled out by Congress. I don't disagree that there are big privacy problems with all of the above platforms.