You shouldn't oversimplify this as "China bad, United States good" because the story is more complicated. Yeah, the origin has a lot to do with China - ByteDance, the company that owns TikTok, is Chinese - but the real problem the US government was raising was about where user data was being stored and who had access to it. There was concern that the Chinese government could force ByteDance to hand over data on millions of Americans, from locations to what they see in their feeds. That's not paranoia; other governments have done stuff like that before, so the worry came from there.
What happened in 2024 was that a law was passed that basically gave ByteDance an ultimatum: sell the app to a non-Chinese company or TikTok gets banned. The government's argument was that it was a national security issue. But here's where it gets interesting: it wasn't necessarily that Biden wanted to wipe TikTok off the map overnight just because, but rather that he was trying to force a change in ownership. It was a pretty aggressive political move, but the underlying reason had some logic to it from the perspective of protecting citizens' data.
The uncertainty was real because nobody knew exactly what was going to happen. People were scared, content creators thought they'd lose their source of income, and ByteDance was also in a tough spot because selling TikTok is super complicated - it's a platform valued in the billions. In the end things kept evolving, but that's what caused all the fuss at the time.