Many (most?) older retail businesses still use TUIs. They're reliable, consistent, and orders of magnitude faster than GUI systems. When I worked ar Sherwin Williams, I got good enough with the TUI that customers could rattle off their orders while I punch it into the computer in real time. It's absolutely crazy that a well designed TUI is so much faster. It turns out that if you never change the UI and every menu it…
This is about keyboard navigation rather than TUI vs GUI, there is no reason you have to render your app with plain text to support efficient keyboard nav.
Variable width fonts and style sheets are nice, though.