"I mean, please, provide me with some novel explanation, something I haven’t yet considered, to help me to understand how, even with all of these targeted resources, a vast, socially damaging problem coalesces and endures?"
Have you considered class warfare? There is a brutal reality being exposed by the pandemic. We are now seeing governments around the world all of a sudden funding programs to keep "the economy" afloat, much like how all of a sudden there were vast amounts of money for fighting WW2. It's well-known that a sovereign country with its own currency can fund anything it wants to, and they often do. So we should all be asking ourselves, why are there foodbanks, poverty, and homelessness? And the unpleasant answer is that these are policy decisions. Do they reflect what may be the true role of government: to keep the people down and the elite in control? Apparently. It's not a secret that in truth there is no shortage of money, but it flies under the radar, and we are living the results of that ignorance.