If you think that GUIs == Flashy, then i think you have a very narrow view of what GUIs are. Also a GUI does not have to be processing intensive and unless you have configured Linux to not use a graphical console and you are not using X or Wayland, you are already using a GUI. It is just that all your GUI does is draw text (which, btw, is among the most processing intensive things that a GUI can do).
