Dude, the concern is that allowing TikTok is quite literally allowing the CCP to indirectly lobby. It's how this whole thing got started in earnest.
https://www.nytimes.com/2024/03/07/business/tiktok-phone-cal...
The geopolitical utility of the app is to give the CCP more power to manipulate and hurt you. They want to get closer to the level of power that domestic US powers-that-be have. I'm blown away that this seems to lost on so many people commenting here
Your interests are probably not aligned with the CCP. The American public's certainly aren't. The Chinese government wants to achieve a hegemony and export their economy and culture by undermining the US wherever they can. We don't fit into that in a way that won't result in a markedly worse life for us.
TikTok would boost content about how Israelis making target practice out of Palestinian children is great and needs to happen more often if it made the US look bad. That you can't see that, or can't separate that instance from other possibilities, is exactly why TikTok is under scrutiny.
Using "CCP" shows your ideological bias.