Because TikTok is owned and controlled by hostile foreign country of communist totalitarians. That country would rather TikTok die than be sold to an operator they don’t control.

The operator doesn’t necessarily have to be American. A European operator would be sufficient. But it can’t be an overtly hostile nation.

All of these arguments have been made ad nauseum.

All social media companies controlled by the CCP will be banned in the US. And since all tech companies in China are controlled by the CCP that means all Chinese social media products will be banned in the US.

It’s not all that complicated. It’s not even that controversial.