I like the list of examples, but I think there are two main points that get buried which the author should have brought out. First, for many things, a command line (or at least a command line with some kind of suggestion facility) is a superior interface to a GUI.
Second, since modern operating systems aren’t designed to explicitly support command line interfaces, apps are left to do it on their own, which results in a hodge podge of various partial solutions. Take for example, the author’s final remark about how the key bindings in various apps conflict. The issue of what keybindings are used to trigger various actions should be disjoint from the actions themselves (and should be completely user customizable).
It would be great if OSs support the Emacs notion of keymaps so that you could have layers of keybindings and a clear way to define your own, rather than letting individual apps have a free-for-all. Spacemacs is an example of a (partially) integrated system that gets a rich command-line interface right.
GIMP (2.9.6 at least) has this very handy menu search tool. There’s a video of an older version here: https://www.youtube.com/watch?v=G0PuH1LFWhA