It's more nuanced than that. The government decided that a population with access to grenade launchers is bad and so they banned all grenade launchers. The law to ban this type of weapons was also approved by the Congress and was not an executive order.

As I said, if Congress passed strict privacy laws that resulted in the ban of TikTok then there would be virtually no outcries.

I think the mistake you're making here is assuming that the United States can only apply blanket policies to all countries and can't treat individual countries differently.

Your aggregation view isn't correct in practical terms. The government (with the consent of the voters, I need to keep stressing that) decided that grenade launchers should be banned, but they didn't decide that all firearms or weapons should be banned. You can clearly see how you can pick and choose categories or different aggregation levels to take specific action on.

It's like, you ban grenade launchers because you don't like the potential harmful effects. You ban Chinese companies because you don't like how the Chinese government treats your country. I think it's pretty straightforward generally speaking. We wouldn't be here if China allowed free reign for US companies to operate in China as we have for a long time allowed Chinese companies to operate in the US. We even only ask that Chinese researchers disclose their military affiliation. In China do you think they'd let US military officers work at top research universities in China? Why wouldn't they? Why should the US?