Is John Rawls' argument for egalitarianism based on the "veil of ignorance" objective?

It seems to me that things like capacities, social position, and earning power, although not entirely under one's control, are largely the function of individuals choosing to delay gratification and put in work. We have all seen gifted athletes blow through the millions of dollars that their natural talents got them, and we have all seen immigrant families start with nothing and put their children in great colleges a couple decades later. We all draw different cards in this life, but the choice to think before acting and act for the long term, rather than the range of the moment seems like the biggest predictor of wealth and happiness in our society, at least. It also seems like that is not the sort of capacity to which the "veil of ignorance" applies.