Shutters have evolved through the years along with fashion trends and window covering needs.
Today people request larger louvers and wider panels for more light and view. Old shutters were often criticized for being "too heavy". New shutters have a lighter more open feel.
If you are looking for old fashion you can still get 1.375" and 1.75" louvered shutters. However, 2.5" louvers serve the purpose and provide better function more economically.