This happens in the US too and has been happening for a very long time (https://en.wikipedia.org/wiki/Room_641A) only when it happens to US companies they get gag orders and/or paid off. (see https://www.theguardian.com/world/interactive/2013/jun/06/ve... and https://www.pbs.org/newshour/politics/report-att-cooperated-... and https://www.eff.org/deeplinks/2022/06/how-federal-government... and https://en.wikipedia.org/wiki/Lavabit)
The content on tiktok is a problem, but there's nothing on tiktok that isn't also on facebook/reddit/twitter/youtube. The difference is that when the servers are in China the US government can't get that kind of access/cooperation.