TUI and CLI isn't the same thing. A badly written TUI will fail to check isatty() on stdin and will dump ANSI escape codes, which are not trivial to remove from the output as they follow a format that has different formats, lengths and sentinels that denote the ending.
I'm fully aware they're not the same thing, I'll not sure what gave you the impression I think they are.
I agree that a badly written TUI is... badly written? Obviously I'm referring to well executed TUIs.
For example, I regularly pipe the result of ls, grep or fd into Helix then use multicursor editing to set up a script. You simply can't do that with a GUI.
