What good is a math result if there’s no human understanding behind it? Unlike many other fields where there’s value to an artifact even if there’s no human understanding, the whole point of mathematics research is just gaining insight and understanding.

On the Navier–Stokes issue specifically, it has long been suspected that such a blow up would exist, and an AI telling you it indeed exists doesn’t contribute any new understanding to the field. And this problem seems like one that would be solved by humans anyways even if AI didn’t exist; accelerating the result by a few months/years using AI doesn’t mean much.