Quality of life wise, what really matters is how secure you feel in regards to family life.
For example, one might likely rather be a ditch digger in Manhattan then a doctor in Brazil that has to live with the daily threat of kidnappings.
And then buy a boat.
1-https://users.nber.org/~denardim/research/Wealthsurvey.pdf - 2https://eprints.lse.ac.uk/68507/13/Karagiannaki_Effect%20of%... 3-https://ifs.org.uk/publications/14954
IIRC, that book cited a study by someone who strongly believed that IQ was a strong predictor of great success...and his own study found that wasn't true. IIRC, he followed a bunch of very high IQ kids from childhood to adulthood, and the most successful of them only achieved middling success.
From Christopher Langan’s Wikipedia entry [1], “In comparing the lack of academic and life success of Langan to the successes of Robert Oppenheimer, journalist Malcolm Gladwell, in his 2008 book Outliers, points to the background and social skills of the two men.” It seems to argue that intelligence alone isn’t enough to succeed.
I’m not sure how middling success is defined, but results from Vanderbilt’s study of mathematically precocious youth over a 49 year period seems to say, “by mid-life they were extraordinarily accomplished and enjoyed a high level of life satisfaction.”[2]
[1] https://en.m.wikipedia.org/wiki/Christopher_Langan
[2] https://peabody.vanderbilt.edu/degrees-programs/smpy_wat.php
side question, why do people who are poor remain in cities and heavily populated areas? Rural areas are much cheaper and the quality of life is much higher generally for the same dollar. Also in the city you and your loved ones are more likely to become the victim of a crime or wrongfully convicted for a crime not committed, addicted to drugs, incarcerated ect ect. It’s also worth noting that most of the US pop lives in city or highly crowded suburban areas, so although not proven its suspectable that most of the leading health related causes of death arise from conditions in those areas.
Moving to a new area is much preferable to an impoverished family trying to fight poverty in a system where the sample size is adequate to predict that they are in essence trying to win against a rigged casino game
I have a property in a very small town around (1000 inhabitants, about 130 kms from the city) and I think it's great: kids can play in the street, I can hear and see horses when I go for a run on dirt roads, nice people, slower living with a close contact with nature. But then again I can work from anywhere and name my price, I have an appartmt in the city and a car and can switch between them as I please.
If you are poor and want to move there it would probably be hell: no much opportunities for a formal job and no one to rely on if you are an outsider... Poor people are not stupid
If you do anything that requires networks of people living in the country will hurt your chances, this even applies to learning about stuff you're curious about, without a community it's way harder to do, and that community just doesn't exist when there aren't enough people. The internet has alleviated this somewhat but for some things nothing beats in person.
There is also something to be said about regional attitudes. If you grow up as the only kid in town interested in Robotics when everyone else your age is into Football, you're going to have a hard time.
This isn't even touching the fact that jobs are scarce in these small towns, unless you are a remote tech worker, but even then good luck getting a decent internet connection, even more so now that some politicians are trying to outlaw municipal ISPs.
Also the stats for country living aren't nearly as spotless as people want to believe, Meth is a big problem, teen pregnancies too, even suicide is high and rising in Rural America. Calling it safer or even more wholesome is questionable at best.
Suicide in Rural America on the rise (2019) https://www.nbcnews.com/health/mental-health/suicide-rates-a...
Drug overdose death rate 10% higher in Rural America (2019) https://www.gatewayfoundation.org/addiction-blog/rural-subst...
Why is Teen Pregnancy Higher in Rural Areas? (2016) https://www.pbs.org/newshour/health/teen-birth-rate-higher-r...
From my brief search (they have a LOT of publications) I couldn't find any publications from them on family wealth as a predictor.
[0]: https://dunedinstudy.otago.ac.nz/files/1571970023782.pdf