You make a good point. A crucial difference, however, is the types of entities and their motives.
A conventional U.S. corporation's motive is to generate profits. Efforts stemming from that motive have not always been in the public interest, and such cases are worthy of regulatory attention, but they typically do not present national security risks. In odd cases where pursuing profits could create national security risks, Congress has sometimes intervened, such as when Nvidia was banned from selling certain processors to certain countries.
A geopolitical entity is not a profit-motivated corporation, so the risk model is different, with national security factors being more salient.
If you can believe that lead pipes contributed to the collapse of the Roman Empire… well, let’s just say the Internet is a series of tubes.
The concerns about TikTok merely as a propaganda platform are naïve and almost quaint when considering what might actually be happening.