So what made them brilliant was largely the usual suspects -- luck and privilege. Good to know.
I read it in a much less defeatist way: A big predictor of success for your kids is to deliberately surround yourself and family as much as possible with the best people you know according to the values and ethic you want to bestow upon your kids.
They're obviously in a great place in their life, but thats hardly "exceptionalism" like Van Neumann was. Tech exceptionals are a different and more selective cohort (you said CEOs).
Take Steve Jobs - he wasn't wealthy, but he spent time alone as a child, and his earlier teachers gave him extra personal attention. His parents would share their interests with him (eg carpentry), and gave him freedom to learn from them and also learn from the neighbors (who were Silicon Valley engineers). He cold-called Hewlett (H of HP) who gave him a job at 13. He was starting businesses in high school for money. Steve was given a long leash to learn, ample minds and talent to observe, and was treated like a self-directed adult as a child.
Someone else who commented on your post used the term “defeatist.” I’d guess it’s even more defeatist to realize if your child has average intelligence, maybe you shouldn’t focus on them being the next Einstein.
Or, from a positive perspective, encourage your child to be who they’re going to be and given them every opportunity you can, and hope they’ll be the happiest, most successful person they can be. Because in the end, there is no recipe for someone to be made into an exceptional person.