First and foremost: That is not what this is about. Well, that isn't what the sane parts of this is about. It isn't that tiktok is too popular.
It is that it is very blatantly a tool of the CCP. Much like facebook and twitter are tools of the US government. There are many articles documenting how facebook has been used to steal elections and... fuel coups. And musk et al are pretty open that they did the same with twitter and the 2024 US Presidential election. And... it is hard to not be suspicious when "tiktok is the only streaming platform that is willing to talk about the genocide in Palestine" and "I refuse to vote for genocide, full stop" were so tightly coupled.
No country should allow such blatant manipulation of its people by a foreign nation. Whether it is the US, Russia (see: RT getting banned the fuck out of most western nations), China, or even frigging Mauritius.
Second... Do you really think People have that much agency? Not individuals, but People.