All problems, and really all actions, can be explained by incentives. Once you understand that people will never under any circumstances do something that both takes effort and is opposite to their incentives, you understand why nearly every problem occurs and why every action is taken.

This statement is either so broad that it is obviously false, or has so many implied additional conditions that its application is incredibly narrow.

* The time horizon used to judge incentives vary person to person.

* Willing martyrs exist for various causes. Therefore, it is not just the incentives that matter, but the belief about those incentives.

* Self-sacrifice for others exists (e.g. a mother rushing into a burning building for the chance of saving her children). Therefore, it is not just the incentives that matter, but also the subjective weighting of conflicting incentives.

* A person may spend a great deal of time researching betting patterns for playing craps, none of which can overcome the house's advantage. Therefore, it is not just the incentives that matter, but the knowledge of the outcomes.

* Somebody may work in an oppressive environment for their entire life, rather than changing careers. Therefore, it is not just the effort required that matters, but also the relative amount of effort on different time horizons.

While I agree that incentives are the best way to move population-level behavior, and is usually a good starting point for understanding individual behavior, your categorical statement doesn't have those caveats.

Billion dollar question is what a better proxy would be.

Possibly a reformed patent system, e.g. one in which time limits are variable or in which you don't get a full monopoly (forced licensing terms). At one point I was researching an alternative patent system in which you don't get a monopoly on the idea, but rather for every next licensee they have to pay in a share of the total value of the patent such that e.g. the first licensee pays half which goes direct to the original filer, the next licensee pays a third and that money is split between the other two licensees, the next pays a quarter etc. So the patent gets cheaper over time to license, but you lose the first mover advantages.

The problem with that system is that the "value" would have to be determined in some independent manner, e.g. an audited cost+ basis, which wouldn't be reflective of the true value of the idea. Granting time-limited monopoly rights allows the idea to be priced via normal market mechanisms, at the cost of high transaction costs.

At any rate, you get the idea. The justification for academic research is that the private sector, supposedly, won't do long term basic science and that grant recipients will. That's a very dubious set of assumptions. We see basic science being done by private labs all over the place, most obviously in AI but also in many other areas of computer science, we see it in the biotech sector, we see it in semiconductor physics etc. The areas where there's no private investment tend also to be the most controversial areas of academia where many people have concluded that the results are systematically useless e.g. social sciences. And meanwhile what we see amongst grant recipients is systematically unscientific behaviour like knowingly publishing claims that aren't actually true, refusing to share data even after promising to do so, accepting unvalidated modelling as 'science' and a million other things.