They seem to be getting higher and higher. There was a time when you could find a variety in heel heights for women from very flat to about 3 inches with the average dress heel being about 2 to 2-1/2 inches. Now most are 5 to 6 inches and as justmesuzanne said "the only people benefiting are the podiatrists and orthopedic.
I saw a news report where few runway models where falling over because of the shoes..
So, why would they be necessary.