AutoCAD amongst other software has been doing this for about 25+ years, I think. Clicky-clicky if you want, or just type in the command, same output.
IntelliJ also, more recently, with its actions input.
IntelliJ also, more recently, with its actions input.
In my personal experience, the search functionality was extremely useful when using for the first time one a complex application such as Gimp or Libre Office. Unfortunately all extra functionalities (autocomplete, for instance) required the applications to explicitly support the HUD and few (any?) application added the necessary code once GNOME 3 appeared.
https://www.youtube.com/watch?v=Hgz2kqm0rsY
20 years ago I remember seeing a person drawing mechanical plans using a lot of keyboard and just a bit of mouse. That seemed really productive.