So what they are saying is that humans, in this case Charles Fefferman (a math prodigy, going by his history), failed to specify the problem correctly?

Article says that there are 2 formulations of the NS problem and both are interesting: one is about fluid behaviour with no external forces, other is about fluid behaviour with external forces.

For a counter-example the latter is easier since you can have a tricky external forcefield.

Betteridge's law of headlines

The goalposts are moving so fast you can barely see them!

Next year's headline: But did Skynet kill all humans?

[flagged]

"AI solved it."

"No we almost solved it."

"No way, it was AI all alone"

"no you used our data for train..."

"Guys, Guys calm! You did not produce any useful results!"