To say nothing of control over how people actually act.

In any case, listening to scientists means you take their input and factor that into the tradeoffs that drive policy. Which may well involve simultaneously that there is e.g. some risk associated with allowing people to travel by air while allowing them to do it anyway.

One of the Biden administration's first moves was to reinstate the ban on travel to the USA from Schengen that was about to expire. And it was just announced that this ban would now be extended indefinitely. The US ban on travel does not just affect tourism, it affects family reunification as well, and I would consider that a hardline approach.

That travel "ban" is riddled with exemptions.

Can you cite those exemptions? There is a longstanding campaign on Twitter (loveisnottourism) that complains that the US policy is preventing partners from seeing one another. Also, even if in some cases one could theoretically board a flight, that means nothing if you need a visa and your local US consulate won’t issue you one, because it says no visas will be issued during the pandemic.