Let me show you an example (gif) I press "Ctrl + space" to open QuickDrop, type "irf" (a short cut I defined myself) and Enter, and this automatically drops a code snippet that creates a data structure for an image, and reads an image file.
https://github.com/b-ploetzeneder/MachineVisionCodeSnippets/...
If you are efficient at this type of input, the "dragging/dropping/rearranging" is similar to refactoring that you would do in an IDE.
The only difference is that there is something called secondary notation in many visual languages (people are not aware of that, I'm only familiar with it because I've done research on the topic - it is how the code is visually arranged). How code is arranged is kind of a quality parameter for visual code (google examples for "spagetti code"). There are typical patterns that are instantly recognizable to an experienced user, ways of using distance and direction to group connected parts..
I actually played with alternative forms of input for LabVIEW, mainly gesture control and "drawing" on tablets. It sounds like a fantastic idea, but only for 5 mintues. After that, your hands start to hurt. The reality is that keyboard and mouse are heavily optimized tools for input (minimal movement of fingers, and we have lots of muscle memory), and don't restrict you. It's like saying "I can type xxx word per minutes" and thinking that typing faster would help you code faster..