> [...] you can build UIs that are snappy and keyboard driven.

That's not an advantage that is exclusive to TUIs; after all, you're running your TUI inside a graphical application that emulates a terminal. (Unless you're rocking an actual VT102, in which case I bow down to you.)

In fact there's an entire class of applications that are extremely snappy and keyboard driven, by their very nature: games.

Some people have taken to writing GUI apps like you'd write a game, and the effects range from OK to fantastic. Check out Lagrange (https://gmi.skyjake.fi/lagrange/), AppManager (https://tildegit.org/solene/AppManager), Dear ImGUI (https://github.com/ocornut/imgui), egui (https://github.com/emilk/egui), and many others.