Chicken-fried steak is crispier with cornstarch

If you choose to dredge your steak in an all-purpose flour mixture that does contain cornstarch, 

That cornstarch will contribute airiness to the mixture that will later result in a super crispy breading.

The cornstarch will also stop gluten from forming in the flour mixture, which will help the flour become even crispier.

If you choose to dredge your steak in only cornstarch, not only will the crust of your chicken-fried steak become deliciously crunchy,

But it will also cook thin enough to complement the thin inner layer of steak.

This means that every time you take a bite of your chicken-fried steak, the proportion of light, crispy crust to tender steak meat will be absolutely perfect.

But that doesn't mean that's all the flavor and texture that you can enjoy