Discover the app that does a specific thing or discover the options inside the app? For the former I don't see how to help except studying what's available. For the latter we've been having man and info since at least the 80s.

Both. GUI interfaces and apps have menus and undo that help with discoverability. To do something equivalent in CLI after not using a tool requires several invocations of man, --help, etc., and checking and rechecking that you hadn't got something wrong that can result in something catastrophic. Stuff like Warp seems like they with that, by interactively displaying most relevant info to help you write the right invocations.