Honestly, the attitude of the math community is a bit cringe and increasingly I think some of the elite/mystical aura is fading. Rather than a rich fertile jungle where AI can barely chomp through a fraction of the luscious terrain, one gets the sense it's a desert and all the oases are running dry.

This is my question too. If we are all just going “well that sucks” after AI solves this problem, why did anyone care about the problem being solved in the first place?

Is the bummer that we got a solution we didn’t want - that navier-stokes is not always applicable or something, but we hoped it was?

The millennium problems is something done by a single institute to motivate progress on known open problems: https://en.wikipedia.org/wiki/Millennium_Prize_Problems