To add another reason beyond just cost of living: Chicago has a bunch of really high quality engineering schools nearby that produce an absolute ton of engineer

To add another reason beyond just cost of living: Chicago has a bunch of really high quality engineering schools nearby that produce an absolute ton of engineers. You have people from UIUC, Northwestern, Purdue, IUB, UWMadison, and Michigan all moving to chicago after graduation. It creates a sort of glut in the labor supply. A lot of them cannot or just don't want to move far away for more pay. A lot of the grads are from chicago or smaller midwestern cities.