In addition to bringing you politics ITT where they don't belong your facts are wrong. Aside from maybe Netherlands, no one has been banning US passports. It's where you'e been in the previous 14 days. If you spent the previous 14 days in a country that allows travel to EU then you're fine with any passport. Just like the current 14 days in Turkey then entry to Malta and onwards loophole. Of course if you have a valid reason or papers you can fly direct from the US to EU.

I don't know which countries are Level 2 or 3 but it seems if you are connecting you'd have to show you have valid grounds to enter the country of your final destination.