So I was poking about in my VSCode settings, File -> Preferences -> Settings. And I found the Workbench > Tree: Indent options which controls the tree indentation in pixels. The default settings was 8 pixels, which is too small for my liking, so I cranked it up a notch to 37 pixels! Yay woo!
Reading about Vim: reformat a Python file to have 4 space indentations and came up with this: