TikTok specifically has ties to the Chinese state apparatus that are concerning, similarly to Huawei. This isn't a blanket statement about Chinese companies in general - just those companies in particular. Specifically, this means these companies' products are likely to be tools of PRC state intelligence and the PRC's foreign-policy directives. The same cannot be said about other Chinese companies and similarly positioned companies in other countries.

This wouldn't be as big an issue if the PRC was a NATO ally, or least had a reputation for government transparency and accountability - and wasn't asserting ridiculous territorial claims - and didn't have an egregious human-rights record - and wasn't actively suppressing freedom-of-expression - and so on. Take away a couple of these issues and TikTok's suspicious business conduct over the past few years would be about the same level as scummy American Freemium game makers. I stress that (and despite appearances) I'm trying not to make a Sinophobic argument.

At the same time, I recognize that companies in China need to integrate themselves with the CCP/PLA/etc in order to succeed in that market.