I just wonder whether a lot of smart people who never needed to go beyond the "solve for X" algorithmic math of a typical calculus sequence are actually reading the declaration the way the signatories wrote it. The Navier-Stokes problem is not exhausted by a simple 'no' counterexample (which most people familiar with the equations already expected to exist). In fact, I haven't heard a single person's explanation for what relevance this counterexample has for humankind. It is something impossible in our physical reality so we have gained zero insight into anything we actually model with NS.

Mathematicians agree that "solving the problem is aligned with humankind." They disagree that releasing a counterexample this way actually constitutes "solving the problem" precisely because there is now little incentive to do the hard theory-building work that actually has the track record of leading to human advancement.