Well, to be fair, GUIS can be powerful commandlines, to the point that they even satisfy most experts. But it needs more work, and you either end up using textinput anyway, or have a slightly worst performing interface. So at the end most invest into the simple solution.

With the raise of HTML5 & Electron and their simplicity for creating powerful GUIs and AI-Speech-Driven interfaces we might be again reach somewhere in the next decades the point where Keyboard-interfaces are in decline. And if the AI overlords take over whe don't have any need for complicated interfaces anyway.