[ezy]

If you have an IQ of 89 or below in a first world country, you might be able to barely complete high school, but are not going to become a math professor.

IQ (g) is normally distributed.

The only hope here is that there is some extrinsic element, similar to nutrition, but as yet undiscovered, that will improve human IQ for those on the left-hand side of the curve in a real way. Otherwise, no, not everyone can contribute in the same way.