Bash already has autocomplete and there are shells with richer feature sets.

What I would like to see is something like CLUI to be integrated with an IDE or a productivity tool like Adobe Photoshop. PyCharm/JetBrains already embraces the keyboard with double-Shift => Search Everywhere, and other similar shortcuts. Similarly, Photoshop would benefit from keyboard interaction for common tasks. We already have single-pixel nudge actions via the arrow keys, but a CLI prompt you could conjure up and type into would be a game changer for actions that require repetition and precision.

That is, rather than bringing GUI to the CLI, bring CLI to the GUI.