I think you need to distinguish between complex systems, and byzantine systems. You can have complex systems where every piece shares a common goal, but feedback loops are hard. You can also have systems which, if a common goal was shared, wouldn't be that hard to understand, modelize and optimize, but where the actors of the system are not acting in good faith.

And I agree with the above poster: often, a problem is described as "hard" as a way to make an excuse for the agents. Sure, the problem is hard. The reason why it's hard isn't some esoteric arcane complexity, it's that some of the agents aren't even trying.

No, I'm not saying the problem is simple, but I'm saying that in many of these cases a systematic understanding of the problem isn't what we're lacking in pursuit of fixes - the reason the problem seems so intractable is because parts of the system benefit from perpetuating the problem and take agency to ensure the problem does not get fixed.

Poverty is one of these, but I think Climate Change is the most direct - the climate is complex, but climate change is simple: we're releasing too much carbon into the atmosphere, we have been for a century, and we've known that for at least half a century*. The issue isn't that we don't have the capacity to model or understand the problem, the issue is that powerful actors have used the leverage available to them within the system to prevent us from making changes to fix the problem.

And, you're right, that makes the problem difficult, because the system includes those actors resisting changes to the system, but again, it's not difficult because we don't understand it, it's difficult because we're being actively resisted by people who do not want to solve the problem, and that should be acknowledged by people looking to make it an abstract mathematical modeling problem.

* This isn't a conspiracy theory: https://en.wikipedia.org/wiki/ExxonMobil_climate_change_deni...