Facebook and YouTube have for years boosted conservative people and posts/videos: this is fine according to the powers that be.
Russia and no doubt countless others run influence operations through all US social media companies: this is also fine according to the powers that be.
China probably runs influence operations through a Chinese social media company: this is a national security problem that needs to be dealt with!!
The reasons TikTok is maybe being banned are because it's the only major social media that isn't suppressing pro-Palestine speech and because it's not owned by a right-wing US oligarch. Musk is the shadow president, Zuckerberg is blatantly sucking up to Trump, etc etc.
I don't trust either of them, but why would they lie about wanting to suppress support for Palestine? And if you don't believe me, the State Department has them on record saying as much: https://www.state.gov/secretary-antony-j-blinken-at-mccain-institutes-2024-sedona-forum-keynote-conversation-with-senator-mitt-romney/