If they are determined to get out of their bad situation, they won't be there forever if they happen to make changes for themselves first. So, that is the first step, they need to change their habits, their lifestyle, their thinking but never change as a good person. With all of the routine that they have, there must be something wrong and that's why there is no progress at all. That's what we have to do, if things don't go accordingly and we're doing it with the same processes and nothing has ever coming out good with it, change is the best solution for it and initiate it. It doesn't have all things to be changed but do it gradually.
It is naive to assume people trapped in unhealthy situations havent desperately tried improving themselves already. Suggesting just change your routine trivializes their struggles and its easy to preach from a position of privilege when you arent the one feeling trapped and hopeless day after day.
The truth is, systemic factors often inhibit peoples growth. Their so-called bad habits develop in response to external pressures we fail to appreciate. Before blaming individuals, we should question whether society has made healthy choices impossible for them.