This is the thing - my window manager can manage windows just fine. I suppose you can make the argument that managing multiple terminals in a tab is a better experience than managing multiple windows in my window manager, but that depends heavily on the terminal being used and the window manager being used.

As a devils advocate in response to all the comments claiming TUIs are fine, maybe consider TUIs mostly do not come with many of the advantages of using a terminal CLI app - you can't pipe data into them, out of them, spawn them and collect the output, etc like you can with the usual stuff you run in a terminal.

IOW, they are a reduced functionality of a GUI - resizing works poorly, scrolling works poorly, UI affordances are poor (sure, you can grey out a button, but drag-n-drop hardly ever works between your various terminal tabs, and the smallest UI element is a full character block, unlike a GUI where you can have indicators that are smaller than a character, mini-windows, etc), lack of widgets, etc.

The lightweight argument is not so good either - look at Claude Code, after all. If you want lightweight GUIs, you can do that too.

The only argument that stands is the ssh one, but if working via a remote connection, I'm not going to want a full functionality application anyway - why would I prefer a wordstar/wordperfect interface to a complex document over a GUI interface? For simple documents, sure, TUI all the way, but when I have multiple panes (outline, minimap, status bars, toolbars, etc), it performs poorly in a TUI.

TUIs are making a resurgence, sure, but only in the context of developers and development.