I don't know why you think it's randomly (or recently) decided -- it started in 2020 (https://en.wikipedia.org/wiki/Restrictions_on_TikTok_in_the_...), culminating in this act (https://en.wikipedia.org/wiki/Protecting_Americans_from_Fore...) banning the app, which passed 360-58.
Have you ever gotten 36 people to agree to something, let alone 360? There's obviously more to this that we aren't aware of.