On the other hand, a citizen should be more scared of his own govt rather than foreign govt because foreign govt won't arrest him. So for an American TikTok is probably less threat than Facebook or Twitter.
I don't even know how you reach that kind of conclusion from that fact. It's not even strictly true. If I travel to China or Russia for a trip there is absolutely nothing stopping them from arresting me. It's only true if you never travel to that foreign country.
In the case of Russia they can do worse than imprison you. Just ask any number of Russia defectors who were killed on on Western soil. This is a very poorly thought out take.
I don’t think they were talking about traveling to Russia or China, they’re talking about living in the US. The vast majority of people will not travel to China or Russsia.
For instance if you discuss doing something illegal like getting an abortion in the US, only the US government really cares about that. Whether China knows is irrelevant.
In the case of Russia they can do worse than imprison you. Just ask any number of Russia defectors who were killed on on Western soil. This is a very poorly thought out take.