the positions that remain, are smaller in number, and higher on the pay scale. its sort of like being a major league baseball player - if you can get in, it pays well, but as a general purpose field that will employ a large number of people - forget it.
A higher pay scale indicates higher demand. Higher demand acts to increase supply. Major League Baseball has a static number of players governed by the number of teams and roster rules. Not so in the market for engineers.