Interesting. If I put it in other words, the argumentation is that AI will just propel the already existing qualities of the people. And because people are different (and the distribution of intellectual qualities remains constant as we grow), the AI will not make any difference on that point.
I'd agree on that.
However, let's imagine the scenario of two people have the similar qualities, with one main difference between them: one have worked longer on those than the other (but their "base" is the same). Do you think AI will propel them at the same speed? (or said in other way: where will be the biggest delta on speed between their pre-AI and post-AI versions?)