Terminals might not have discoverability, but in terms of sheer power they wildly outmatch GUIs for many tasks.
I suspect if all technical users simply stopped considering text based ui acceptable, we'd actually have less quality software overall. There are too many programmers like myself, who can make decent programmatic interfaces, but simply can't put together a usable web-interface to save their life.
Graphical user interfaces are a caveman interface. You go to the market, see what's on offer, point to it and grunt. That's fine as long as you see what you want. But you'll never do anything that you can't already see.
It's not easy, though. Nobody pretends that it is. But learning to read and write wasn't easy either and you managed that. What if our education systems didn't enforce that? How would you ever know the power you're missing out on?
A language to do stuff is actually a great thiing, especially if it can produce readable and reproducable objects (programs). However, I get really scared looking to most commandline scripts. It's an incomprehensible mess people only can start to grok after years of experience with the particualr commandline tool.
And how is this different for GUIs? Location / icons / description / ... depends entirely on the application. Some will have hotkey handles, some won't. Same app on a different system will look differently. (Possibly with different layout) Creating a discoverable GUI takes as much will and attention as a good set of CLI options.
I would spend far less time at my computer (would only use it for work) if it only had a CLI, but I would never, never use a GUI (beyond text editors, of course) for most of the grunt work, the CLI is simply faster and, and this is the most important issue, almost everything you do with it can be automated.
I couldn't even begin to imagine having to navigate the endless dialogues in IDEs to configure every little thing I would do in the command line, I'd give up programming altogether.
For full TUI applications I'd agree, there are usually worse at discover-ability, they are used because the make up for it in other ways like speed and learn-ability.
As an example of composability... Say you have an api that returns products, but you want to find out how many have the word aliens: curl # gets the api responses grep # searches input wc # counts input. jq # parse and query json
Streaming those together:
curl api.myapi.com/products | jq .name | grep 'aliens' | wc -l
Most of the commands are also mnemonic -r is usually reverse, -R recurse, -a all.
I recently in 5 minutes took the API response from one api and constructed sql queries into a test db for test data using roughly the above method. Another fun, trolling type command, a product manager that wanted daily updates got a scrum.sh that ran on cron and posted summary of what people did on slack.
I don't know how you can work effectively as a software engineer without knowing something about it.
I never understood the appeal for terminals. Often (Microsoft's Powershell is a notable exception) the syntax is full of incomprehensible abbreviations, the syntax is wildly inconsistent, the syntax contains hard to remember acronyms...
No, for me, terminals and most textbased interfaces will never be as usable as GUIs.