Indeed, spaghetti is a big deal. However, in systems like [Node-Red, Antimony, Apache NiFi] you can make function nodes that abstract out the actual data vs the function. And then, your function primitive can be called and instantiated for the particular purposes.
I know in Antimony CAD, you can even instantiate a function, edit the function's flow or individual python subroutines, and the delta is saved for that instance.
I know the hardest graphical programming I've had was with the Lego Mindstorms ev3. There were multiple "simplifications" that removed functions along with a nigh-unusable gui (the if block was this huge encapsulating thing, and other branch codes also had onerous things on screen).
I know in Antimony CAD, you can even instantiate a function, edit the function's flow or individual python subroutines, and the delta is saved for that instance.
I know the hardest graphical programming I've had was with the Lego Mindstorms ev3. There were multiple "simplifications" that removed functions along with a nigh-unusable gui (the if block was this huge encapsulating thing, and other branch codes also had onerous things on screen).