Lines of code are essentially doing the same thing as boxes and arrows. It's just a different representation of the same idea. You can see pretty direct translations in programming languages like Scratch, Unreal Blueprints, and Godot 3's visual scripting. As well as logical implementations in tools like Davinci Resolve Fusion.

I think most programmers find this logic easier to type out than to "draw" in a graph, but it's conceptually the same thing.