It quite literally is political. It’s not legal for them because China but Meta, X, Snap, etc can do the same thing (plus more, Cambridge Analytica, for example) and be fine.
That is the definition of political, and anyone that told you it was to protect your privacy was lying to you, just like this article explains.
Also, do you think China has to buy the data from these companies? And even if they do buy it, what makes you think they do it all above board? Do you think they won’t just bribe and steal their way to your data?
The problem was never TikTok alone. The problem is social media corps altogether, and the fact that the government doesn’t actually give a shit about our privacy (probably because of the lobbying that these companies do, also explained in the article). If the US government cared, we’d have laws preventing much of this data from being collected in the first place.
Did you read the article, which mostly talks about these companies as a whole and not just TikTok?