I'd qualify as smart depending on the metric. I actually went to a private school (the public schools in the area were complete garbage and out of control - bomb threats, drugs, etc at the middle school level). It really wasn't that challenging and most of my useful knowledge beyond the basic read/write/math is self taught. Most of the stuff I learned in college was never used. Using those innate skills at a young age produced nothing tangible. I won't achieve any real success in life even though I checked all the boxes when I was younger - smart, good grades, extracurriculars, family, religion, went to college, etc.

Really all any good school or parent can do that is helpful is teach their kids to want to learn and how to self-teach. Most schools are terrible at this and just want to hit test scores and follow procedures/regulations (learning environment can be atrocious). I'd say most parents are average at this.

The real question is, what do you think would be different and why can't you achieve that now?