https://www.gnu.org/software/libc/manual/html_node/Getopt.html
That said.
I think CLI programs are user friendly for professionals. Because they support input-process-output. Where input is STDOUT read by human, process is thinking by human and output is keyboard input to STDIN by human.UIs for the general audience? TUIs! TUIs are easily to parse, succinct in organization and fast input - all for humans. Humans can parse TUIs. And they can make up a mental modal.
GUIs fail often with a lack of organization, information overflow and distractions by weird metaphors. The Windows 95 desktop metaphor is an example. It doesn’t make sense. Same for Windows 11 and its file-browser which makes it hard to recognize the filesystem or even just the home-directory. Now open Nautilus on Linux, it opens by default your home-directory (in most cases the place to be).
I like the CLI but TUIs are my love. GUIs are okay if are like a TUI.