the big thing ive found with block/visual programming is that it basically only supports scripting languages and imperative graphs, where statements occur after another as a child on a graph with bare minimum support for loops or logic. theres no thought on how to display definitions or inclusions, or things like macros, or compiler directives. its not a bad thing, and actually works great for several things (blender with geometry nodes and materials, houdini, etc), but isnt suitable for complex software beyond scripting within it.