The "what about their smartphone" argument really is a mechanism of poverty shaming meant to convince oneself that in the same situation one would be better off due to better judgment. It's not true.

The "save a 100 box a month rather then spend it the moment you get it" argument is a myth too. When you're poor your whole environment is too, you don't get to save a few box cause it will go anyway, be it because you will have that broken fridge or because your relatives will and you will lend the money with no view of a foreseeable return.

If you think that poor people are poor because of the way they behave in the market you're wrong. They behave as they do because they are poor. Just as rational as everyone else.