I don't really think you or Terry knows what hard work even looks like. We hold this conversation about personal advancement from positions of extreme privilege while billions live without running water. If you want to limit your view to only those of us with access to all the delights of modern society (and none of its externalities) I'm sure you can find plenty of evidence for the meritocracy.
You can personally thank my grandparents, all four laying dead in their graves before the age of 60, for your opportunity to "work hard" in America.
I've got a friend who is in industrial maintenance. I just can't understand how they put up with the working conditions. 12 hour shifts working around furnaces and covered in grease all day, forced overtime on a regular basis. This guy works harder than I ever have and makes a fraction of the income that I do. He has been injured multiple times at jobs. He's in his early 30's and has a more difficult time walking than many senior citizens due to a back injury. To your point he's still better off than many folks in similar situations in less developed nations. There's a lot of detail left out of the "work hard" narrative.
You can personally thank my grandparents, all four laying dead in their graves before the age of 60, for your opportunity to "work hard" in America.