Thank you @GogoVega. But this is not what I was thinking. Subcategories does not eliminate vertical scrolling, and can increase the time spent opening and closing categories to find nodes depending on how developers subcategorize their nodes, and the number of levels they define.
When you dont know the available nodes in the environment you are working, you probably use the palette to access the node's documentation, right? Once you are familiar with the nodes in your editor, you switch to typing because it is faster. I know typing is faster but I still like to drag and drop nodes.