Some income disparity is good for the reasons you stated. I’m fully on board with a society where people can move from lower middle class to upper middle class. But too much and you’ve got people commuting 2 hours to serve fast food because they can’t afford to live anywhere near where their job is. Too much income disparity means some people make more than they can use and others make less than they need and areas crumble like that. If full time work doesn’t mean you get to live inside with less than ten roommates why not commit some crimes.

This also ignores the privilege inherent to being able to make these choices comfortably.