Europeans used to make Americans look dumb.
If we're going by generalizations and stereotypes then sure, stereotypes change over time. Some don't but some do. Some change only a bit over 2,000 years and some change completely in 5. Some are rooted in the truth, some are rooted in hate, some are probably rooted in alcohol, and some are rooted in whatever.
There are stupid Americans and stupid Europeans of varying degrees. There is a wide array of stupidity emanating from both continents and there indeed appears to be a lot more of it out there these days, but personally I think the average intelligence level is actually going up in most Western countries. What's happening is it's easy to assume that the small glimpses you get into another culture give you a good understanding about any significant part of it. Lots of stupid things are done every single day by millions of people on both continents, but that's been happening for a very long time, like basically ever since humans started walking around and doing things. Human beings excel in stupidity. Individually there are a lot of idiots on this planet, the only reason anything's been ever achieved, like agriculture, space flight, etc. is because human civilization has made us into a sort of super-being that has a mind of its own. It's easy enough for the media to focus on only a small percentage of all the stupid things done by human beings and push some sort of a narrative that ignores all the other stupidity that has been achieved.
There is also now a more global and connected social media in place, which adds even more layers and complexity to our perceptions of other people around the planet. Things are shifting and you're responding to media-influenced interpretations of events, and a secondary feed-back loop being created when the politicians voted into office respond to similar media pressures.
See, now it's complicated. So it's easier to just go with "When you're trying to compare the cultures of two continents such simple and black/white answers are probably very far from the truth"
Also "Both continents have been trying out-stupid each other for a while now and both are succeeding in different ways"