There is lots of jingoistic claptrap that supports this view.
That doesn’t mean that millennials are right to support socialism, of course. But you have to hold two seemingly contradictory thoughts on your head at once: that individual millennials will be better off in the long run if they dont see themselves as hopelessly put upon by powers outside of their control AND there are powers outside of their control that are the results of deliberate policy decisions made by previous generations, and this require a commensurate policy response.