I don't think Tiktok will bring about the end of America as a functioning country. I do think Facebook's executives have an interest in gaining control for themselves at any cost, up to & including the end of America as a country if that is the most profitable route for themselves.

Put another way, I think China & Facebook's execs are about equal in terms of danger to US citizens (I'd probably give the edge to Facebook's execs, since they have direct control over US policy, but we're splitting hairs here). So banning one but not the other is a crappy situation, because it concentrates that power even further.