Where would you rather live? A society where the rich are extraordinarily rich and the poor are very poor, or one where the rich are merely very well off but even those on the lowest incomes also enjoy a decent standard of living?
For all but the most ardent free-market libertarians, the answer would be the latter. Research has consistently shown that while most people express a desire for some distance between top and bottom, they would rather live in considerably more equal societies than they do at present. Many would even opt for the more egalitarian society if the overall pie was smaller than in a less equal one.
On this basis, it follows that one good way to evaluate which countries are better places to live than others is to ask: is life good for everyone there, or is it only good for rich people?