TUIs are much closer to GUIs than CLIs. As a CLI enjoyer, I was resigned to the small win that at least many people distinguish TUI and CLI now but then I saw your comment.

There are quite a few GUIs that can be navigated with keyboard, e.g. menu bars can usually be activated with alt or win and single key presses

As I said, the advantage of the TUI is that they avoid context-switching.