Earlier quoted context omitted.
Solvers aren't magic. But it turns out that many naturally occurring instances of NP-hard problems aren't the "really hard" instances that the NP-hardness proof depends on. Solvers can also fail for really tiny problems. You simply have to try to figure out how hard (or how well adapted to the solver's heuristics) your particular problem instance is.
I’m saying this because most people got from their CS degree that NP hardness is practically a death sentence. But it‘s really not true. Even if the problem is proven to be NP hard (or worse) and every previous approach has failed. There can still be some trick or technique (non heuristic!) that brings a breakthrough. Maybe you still wait 10^whatever years for a solution in some cases. But if you get an answer in sec…
It's a death sentence for economists, since they rely on every agent optimizing the entire economy of 8 billion agents in real time. 3 hours for 8 million variables isn't real time.