I'm American and have lived in Europe for 15 years. I assure you there is every level of educated/not educated (crystalized intelligence) and every level of very bright and pretty slow (fluid intelligence) over here, just as there is in every country in the world. Being educated and being intelligent are not the same thing.

Europe is not one place either, take a random Dane and a random person from Italy or Portugal or Croatia or Scotland and put them side by side and tell me thats one culture, ya know?

To your point, though, I will say that the quality of the foundational education in the US does pale pretty quickly when compared to the majority of public education systems that I'd be aware of here. I've been pretty embarassed about how limited my knowledge of geography and history has been at times while talking to some of my Italian, Irish and German friends.

I am friends with a primary (elementary) school teacher (teaching outside of Hamburg) and she expressed that she's seeing a rapid decline in the students' interest, work ethic and thus their proficiency in the past few years. She's genuinely alarmed. We might start seeing articles like this about mainland Europe in a few years.