Inequality has been cited as the most important single explanation for the huge difference in the prevalence of social problems. The data tells us that societies where the gap between richest and poorest is smallest have better health and social outcomes (for everyone) than less-equal societies.
Not dealing with poverty means everyone suffers.
“In a more unequal society, even the middle class on good incomes are likely to be less healthy, less likely to be involved in community life, more likely to be obese, and more likely to be victims of violence. Similarly, their children are likely to do less well at school, are more likely to use drugs and more likely to become teenage parents.” (Source: Professor Richard Wilkinson)