TUI is easy to train on, but hard to use for users. Part of the reason it’s easier to have LLMs use a bunch of Unix tools for us is that their text interface is tedious and hard to remember. If you’re a top 5% expert in those tools it doesn’t matter as much I guess but most people aren’t.
Even a full-featured TUI like Claude Code is highly limited compared to a visual UI. Conversation branching, selectively applying edits, flipping between files, all are things visual UI does fine that are extremely tedious in TUI.
Overall it comes down to the fact that people have to use TUI and that’s more important than it being easy to train, and there’s a reason we use websites and not terminals for rich applications these days.
I use headless mode (-p) and keep my named shell histories as journals (so no curses/TUI or GUI). But session management or branching could improve at the tool level and allow seamless integration with completion tools, which could be a simple fast AI looking at recent sessions or even be visual, say for navigating and extending a particular complex branch of a past session. It is not too hard to work with such shell-based flows within Emacs for me, but it would be nice if there was some standardization effort on the tool fronts and some additional care for future automation. I dont want my AI clicking buttons if it can be precise instead. And I certainly want multithreading. I think of AI more as an OS; it needs a shell more than it needs windows at this point in time.
all the examples for visual UI, are tasks which already are (or soon be) done by the agent, not human. hence not needed.
I suspect that final(*) UI is much more similar to TUI: being kind of conversational (human <> AI). Current GUIs provided by your bank/etc are much less effective/useful for us, comparing to conversation way: 'show/do me sth which I just need'. Not to mention (lack of) walled garden effect, and attention grabbing not in the user interest (popups, self-promo, nagging). Also if taking into account age factor. Also that we do not have to learn, yet another GUI (teach a new bank to your mom ;). So at least 4 distinct and important advantages for TUI.
My bet: TUI/conversation win (*).
*) there will be some UI where graphical information density is important (air controller?) especially in time critical environments. yet even there I suspect it's more like conversation with dynamic image/report/graph generated on the go. Not the UI per se.