The reality is that they lack the cash to quit. Drink, drugs, and alcohol are used as coping mechanisms to make life bearable. When people move out of poverty - for whatever reason - a substantial proportion suddenly find the self control to change their habits.
https://www.independent.co.uk/news/poorest-families-more-lik...
The reality is that there is some wiggle room for sacrifice and saving that is not unreasonable. My next door neighbors are on Maryland's public assistance for housing program (which places poor families in middle-ish class neighborhoods), so they pay little to no rent. They live off of food stamps. Yet they smoke, drink, use marijuana every weekend, and play lotto (I know because they litter the used tickets on the ground).
Are all of those coping mechanisms necessary to make life bearable? Or just some of them? Is there some room to exercise free agency and periodically forego one or some of them to save a little extra cash so they aren't constantly in crisis? I say yes.
How is saving $1000 a year going to help some poor person who lacks education, or opportunities?
Anyway, the whole point of this thread is that having some buffer money allows you to make more optimal savings choices in the future. It's a cascade effect.
Even $1000 in savings as a buffer would allow you to make better decisions grocery shopping (you can afford to hold off and wait for better deals, etc.) or in the case of this article, have the patience to forego $100 now to get $200 later.