Don't companies like Glassdoor solve this problem? You don't need to know everyone's salary as long as you know the average, median and maximum in a specific co

Don't companies like Glassdoor solve this problem? You don't need to know everyone's salary as long as you know the average, median and maximum in a specific corporation in a geographical area. I don't see how making everyone's salary public will help more than knowing the average/median etc.