Social collapse seems to be characterized by wealth disparity, inadeqiate wages for non-elite workers, failing governments, debt defaults, resource wars and epidemics.
Inflation -adjusted oil prices are now much higher than they were 50-70 years ago, and this means that the contest BETWEEN DOMINISHING RETURNS AND EFFICIENCY has basically been won by diminishing returns for the last decades.
Paying higher prices for everything due to diminishing returns can be hiddedn for a while if the economy is growing, as well as debt. But this adds complexity and debt to the system, making it less and less sustainable.
Growing complexity increases wealth disparity. This is because an employer needs to pay high wages to supervisory and skilled workers. This leaves fewer funds for the less skilled workers.