Our brains are not wired to excel out the box. This is a genetic failsafe built in so that we can adapt to any environment we find upon leaving the womb. Therefore, it only stands to reason that we have the most to gain from integrating experience into our cognition, and the better the quality of that experience, the better our cognition becomes. That's not to say baseline intelligence won't have an effect- it will. Baseline intelligence will also persist to an extent, even in situations where useful environmental feedback is null or next to null. Nurture is incredibly important to development. It can't be understated.
Many people i being one of them are innately smart . And some people are innately dumb . The environment can cause expression of a trait but people who are innately dumb can't go past a threshold no matter how the conditions were so genetics is the maximum and the minimum and enviorment is the expression