I doubt that even close to 50 million Americans know what bitcoin is, even if some of them might own some.
Perhaps there are closer to 10 million American that might have significant exposure to bitcoin, and have some kind of actual clue about what it is and why they own it
I also agree with you that Americans are ahead in almost all aspects, I would like to add to you that people living in America are getting more benefits from every economic aspect. It seems to me that the real reason for this is that because America is economically prosperous, they get more of any economic advantage and in most cases get it first.