Success comes down to a hell of a lot more than IQ.

While success and IQ are almost certainly correlated, it is not possible to make a statement like that.

You can just as well say that success comes down to height, or country of birth, or combined wealth of uncles. There are so many other factors at play.

Plenty of smart people have died in childhood for reasons completely out of their control, which makes them pretty unsuccessful by any metric.

> Success comes down to IQ

I think it arguably more likely that acceptance into the education system comes down to IQ due to antiquated practices in attempting to derive intelligence. Being within the education system is the sunny uplands to networking and generally better opportunities.

Its possible that almost every child has the potential of a "good enough" IQ and that nurture reigns supreme over the supporting cast of genetics. To separate the two within nurture there remains environmental factors such as an interpreted narrative of favouritism which can lead to downward spirals.