However the point really is, do there really need to be issues at the border when flights land? I guess you could exempt travellers so that there is the appearance of normality to people IRL, but that wouldn't prevent issues at the border for packages, and most people get a lot more packages than they do fly in/out of the US, so I'd imagine it wouldn't take long for people to really notice the impact directly (let alone several steps removed as companies can no longer import effectively).
Or not! But I don't think the problem is that we cannot craft regulation, it's whether we ought to.
On the other hand, that point is not as legitimate in the US as in Europe due to domestic companies such as Amazon that don't act in good faith. Stores that pretend to be marketplaces and therefore try to avoid responsibility for the stuff they sell for their subcontractors.