I am so envious of you guys who have travelled extensively internationally. I've been to Italy 3 times, France, England, Spain, Bermuda, St. Maarten, St. John, St. Croix St. Thomas, Bahamas, Mexico, Canada, but it doesn't seem like enough. I did visit Vatican City, and had a private audience with an important person, so that makes up for a lot of it.
Fortunately, my job has me travelling domestically, sometimes to very small and remote places that most people have never visited. In doing so I've seen some amazing places, and met even more amazing people.
I work in international travel but haven't really been that many places, Australia (25 times), New Zealand, UK a number of times, France 3x, Germany, Portugal, Macau and Hong Kong a number of times. Those of us in international travel don't count Bermuda, Bahamas, Caribbean, Mexico and Canada as international so I won't even go into those. Anything you didn't really need a passport for before recently doesn't count. You might as well throw in Hawaii (10x)
But having traveled enough and a lot domestically plus working in the industry I can say that while there may not be that much in the way of historical attractions or culture in the US compared to a lot of places the natural beauty of the US, especially the national parks, and the diversity is something international visitors marvel at while many here take it for granted.