There was a video about this posted a bit ago. The speaker said basicly this same thing. After the age of 7, the environment that your kid is placed into, and the other people they are around, has for more influence on them that the parents have.
You do your best for the first 7 years, and then you do your best to find the right environment for them for the rest of their lives.
My opinion is that every child is different - there is no one size fits all formula that will work for every kid. You can only imagine that things MIGHT have turned out differently if you did something differently, but you have no way of knowing that. As a parent all you can do is ask if you did the best you could.
I have 2 young adult children (20's), and in retrospect I can see a few things we could have done better, but otherwise kept them safe, healthy, and I personally always pushed for them to be independent. I'm of the belief that there is no perfect way to raise a child. You can follow every line of wisdom, and still not get the results that were supposed to be the outcome of said wisdom.
I also firmly believe that our environment is extremely toxic. Both socially and literally. Short of raising children 1000 miles from a city, perhaps a farm in the middle of no where, there is very few options for a healthier environment. Unless you are inherently wealthy, or grew up in a place similar, and are able to pass that lifestyle down...
I'd like to go one step further and propose that the amount people are affected by nurture is part of their nature. Person A may be born with murder tendencies and grow up into a murderer no matter what, even while being raised watching Mr Rogers. While Person B may be born with murder tendencies but may only grow into a murderer if growing up in a murder enabling environment like Detroit or being filthy rich.