I use IDEA for most things and barely touch the mouse. It has its problems (like terrible performance), but it's a good example of a GUI done right.

Everything can be controlled through the keyboard, typing into every window does fuzzy search of its contents (and that window might contain a list of code symbols, a list of database tables, a list of search results, or many other things).

Every action can be bound to a key combo of your choice. Every interaction with the GUI can be stored as a macro, edited and replayed.

And so on, and so forth.