Just an observation on my street,
We have quite a range of folks in the 25 houses that make up my two-pronged cul-de-sac. There are a half dozen or so VERY wealthy households. We're not talking about high income, but high net worth. The parents of the Gray kid recently dropped $1.5M in renovations on the house.
The families with money mostly have adult kids, and none of them are worth a crap. Several of them didn't manage to finish high school, most of them have criminal records, and I can't think of one of them from those half dozen households that, as adults, actually contributes to society in any positive way perhaps past the economic benefit of blowing mommy and daddy's dough.
This is MY observation, limited to my street. Yes, rich kids can do well. It's about parenting, and the folks on my street parent through buying crap, nothing more.
The lesson is that yes, SES (socio-economic-status) of the parents is the number one influence on the success of the children, don't take it for granted.
BTW, the family of that kid also has dogs, and yes, they're vicious. Everything they come in contact with hurts things. Hhhhmmm...