The solution is none. There is no "solution" because it, in itself, is not a problem. The problem is that everybody feels entitled to a top 10% salary and many would kill for "their fair share" when nowadays even the lower 10% have their basic needs covered and some left for leisure.
The problem is that a society where everybody have similar incomes is somehow fairer, when there is no logical chain leading there and to top it off it causes ruination. Did cause it already just after industrial revolution, when this disparity in productivity first became natural, and does more and more now.
Having everyone highly educated would solve many things. Not salary disparity though, as it isn't a problem in the first place. The problem is having a significant chunk of the population hungry or homeless. This can perfectly be eradicated "even" with a higher disparity.
The problem is that a society where everybody have similar incomes is somehow fairer, when there is no logical chain leading there and to top it off it causes ruination. Did cause it already just after industrial revolution, when this disparity in productivity first became natural, and does more and more now.
Having everyone highly educated would solve many things. Not salary disparity though, as it isn't a problem in the first place. The problem is having a significant chunk of the population hungry or homeless. This can perfectly be eradicated "even" with a higher disparity.