A lot of the comments here come from a place of ignorance...
I've had the unique experience of private tutoring many "elite" students in high school for math and physics for nearly a decade in Los Angeles a while back. Basically both rich kids and less fortunate kids who can only afford my tutoring rate every once in a while vs rich kids who can if they wanted to afford my help every day.
It's not simply "better textbooks" or "better schooling", the difference in education is VERY DRASTIC and being in LA I was able to see kids from drastically different backgrounds. Rich kids with having tutors for every class, maids for every other side chore so parents can actually pay attention to their kids, private high schools and middle schools that cost nearly $30-50k per year can buy you so many advantages most people can't even comprehend.
The biggest advantages I saw was better resources, better textbooks, curriculums that are ACTUALLY made with care and time, and most importantly teachers who were paid very very comfortable (ie, 6 figure salaries) who have the luxury to not be overworked, and can actually attend to their students as needed. Imagine every one of your teachers in middle school and high school, putting top notch effort into providing a great learning experience for you? Most people probably only had one teacher like that in their entire lifetime. And not to mention if the school was lacking in any area, many of the rich parents would hire their own private ex-olympian or ex-superstar specialist of whatever they desire.
People here are DRASTICALLY underestimating what extra educational resources can buy.