The practice you recommend was basically codified as IBM Common User Access, now recognized by some as the UX convention of IBM mainframe software --- one component of CUA was a list of available actions and their assigned function keys, at the bottom of the screen. CUA itself was not widely used, but was highly influential in IBM's greater orbit of software vendors, including Microsoft. As a result, many, but not all, Windows GUI conventions and keyboard shortcuts come from CUA, and this is its lasting legacy.

That CUA was originally defined for text-mode applications as well, and indeed was based on loose conventions that had emerged within IBM for text-mode applications, has been largely forgotten. But even in the '80s there was an appreciable divide between the IBM paradigm, which was more oriented towards menus and actions (what we think of as GUI today), and the AT&T/UNIX paradigm, which was more oriented towards composition of commands.

Of course there are things like newt which have crossed the lines, but generally speaking UNIX derivatives such as Linux have tended to "stay in their lane" of command-oriented environments with minimal user assists. This could be seen as a long-lasting influence of the different I/O paradigms these platforms tended to feature in the influential '80s: UNIX systems were built around line input and output (e.g. TTYs) while IBM systems of the same era were more often built around video terminals (e.g. CRTs). This was basically because UNIX was predominantly running on hardware of opportunity (e.g. whatever the institution already had), and thus had to be flexible and not assume much, while IBM systems were more often used with terminals leased from IBM along with the machine and thus could assume the latest era of video terminal capabilities.

And then, of course, sometime around the '90s all of these platforms more or less ossified in their differences from each other, as each respective camp came to view their UI paradigm as a core feature of the platform which should not be modified.

This is just one of the ways in which UNIX and its family are much more "line-oriented" than even many of their contemporary competitors. This was partially by necessity but also partially by design as the line-oriented paradigm was easy to understand and work with, conceptually if not in practice. Ironically line-oriented input and output is often justified as being reminiscent of punched cards, when the software lineage with a far longer background in punched paper media (IBM, CDC, etc) were far quicker to get away from this model of human-computer interface than UNIX.

Put more generally, "GUI" vs "TUI" is to some degree a false dichotomy. Many of the real capabilities and interactions we associate with GUIs are also quite possible in TUIs (although the GUI version is clearly a refinement), and indeed were often implemented prior to the common availability of raster displays. When people talk about "GUI" vs "TUI" they are almost always actually talking about differing fundamental UI paradigms, which I might call action-oriented and line-oriented. Each can be implemented in a raster-mode or text-mode environment, although both generally work better in a raster-mode display (we might consider Jupyter to be an example of a line-oriented paradigm on a raster display).