People here keep calling for banning of Tiktok, but I don't get it. Why do people call for a discriminary approach (targeting Tiktok solely based on its origin, not giving them a chance to prove innocence), when that's totally unnecessary?

Yes, the US is allowed to have national security concerns. Yes, the US is allowed to distrust China for whatever reason. But you could draw up a law that says "ANY foreign app must go through a security audit to certify no data reaches any foreign governments". That way you don't just target China, but also targets hypothetical Russian, European, African or whatever apps that could be problematic. And Tiktok would then be able to prove innocence or fix leaks.