Also when someone is barely getting by, assuming they are not dealing with addiction or violence and generally just subsisting, you can bet they know exactly what to do with that last $20. E.g. groceries with the highest calories per dollar, how many bus passes to get at a time, etc.
If budgeting is what is meant by investment (since obviously we're not talking about saving if there's nothing to be saved), from what I have seen poor people are incredibly good at it.
Contrast that with money managers who are generally just bad and can't outperform the market, not for lack of trying. Is "investment" really the right idea, and who says it's the number one importance compared to basic human needs?
Why does everything have to be about abstract efficiency and cost? It's not like there's a shortage of business opportunities for techno-luxuries that are fun to produce and trade, that we absolutely must go after basic rights via austerity. Lousy rentier mindset, we should have to be creative to profit. Once monopolies emerge they should be broken up, and once technologies become necessary for daily life, access to them should become a right. Tax incentives to invest in R&D instead of hoarding wealth could be expanded. So many things can be done to mitigate issues within "social democracy" without going full public ownership or eliminating private property. Question is, once these things are implemented, how can their repeal be prevented? Time to open up and revise constitutions.