I agree. In the CLI I have a blinking cursor. If I press keys I see characters. If I press enter I get a response[0]. I do need a further invocation to get help, but that's easy enough.
[0] admittedly a holdover from the typewriter, but even presented only a keyboard and a screen I've had a kid realize that one special key makes the words go vertically instead of horizontally.
There is no reason why a better shell couldn't show tool tips over command names or flags, assuming there is support for it in a terminal emulator. Even without support from the tooltip it would be possible to show some info about the thing below the text or mouse cursor in a designated area of the cli.
[0] admittedly a holdover from the typewriter, but even presented only a keyboard and a screen I've had a kid realize that one special key makes the words go vertically instead of horizontally.