Your beef appears to be with over-abstraction and not functional programming. FP generally makes debugging much easier because the state of the system isn't cha

Your beef appears to be with over-abstraction and not functional programming. FP generally makes debugging much easier because the state of the system isn't changing in unexpected ways underneath you, so you only need to look at local state. A "functional" recipe is just as simple and straightforward as an "imperative" recipe. Over-abstraction on the other hand, can be introduced with imperative object oriented programming just as easily as with functional programming.