Anything as complex as an operating system is going to have far too many features for them ALL to be easily discoverable. For something that complex, you want the most fundamental features and the most-used features to be easily discoverable, and everything else doesn't necessarily need to be. I've used many different versions of the major operating systems, and this seems to be true of them all, and is not macOS-specific.

As to why "Mac users are so delighted when they discover previously-unknown features"... I think it's partly because Apple (usually) does a good job at adding features. It often feels like they've refined the OS, not like they've simply jammed more things in.

Also, I think it's in part because when you get used to using a particular version of the OS, you might get used to not having certain features built into the OS. So when you discover that something you had previously been relying on a third-party app for is now built in to the OS, it's a pleasant surprise. While this isn't actually a Mac-specific thing, I do feel like Apple puts a lot of features into their OS that other OSes rely on apps (or even third-party apps) for, so maybe mac users might have more occasion to discover that something is now built in?

Easy to use technologies are simple. Powerful technologies are not.

Apple’s trick is to make powerful things seem simple. They do this by, basically, hiding a lot of features. This makes it easy for unsophisticated users to get going. And power users are willing put in the effort to learn more (that’s what defines a power user).

Apple is hardly alone in this. The “full-page screenshot” feature of Chrome is hidden like 3 clicks deep inside the inspector.

If you just use the system app, Screenshot.app, then all of these shortcuts are first-class menu items within that app.

You can configure the mapping of cmd-shift-4 (or whatever it is) to the screenshot function, within System Preferences. Along with whatever other specific keybindings you want. It’s not emacs-level customizable, but it’s functional.

It’s actually pretty standard keybinding config stuff.

My reaction when I discovered these shortcuts as a Mac user coming from Plasma was the same as yours, 'what a bizarre, undiscoverable way to do things'.

When macOS finally got a flexible screen capturing app (now bound to Cmd+Shift+5) Mac users were rightly very pleased. But we'd had that as the default, highly discoverable behavior on Plasma for more than a decade, and the equivalent on Windows was already old news, too.

Maybe it was just hyped too much, and maybe the similarities to Linux just put it in a sort of uncanny valley for me that spoiled what could have been fun. Maybe it was the pressure of trying to learn an OS while onboarding at a new job that stopped me from learning macOS at my own pace that really drove my frustration. But I was left feeling very disappointed by the much fabled UX and design of macOS.

They are perfectly discoverable, what with the Screenshots being done through an app named - you guessed it - "Screenshots". These kind of bloggers just like to pretend they're hidden in order to sell their "expertise".

what do you want for "discoverability"? some random popup when taking a screen shot is the furthest thing from your mind? things like this are simple to find. just open the list of keyboard shortcuts or search in help for what you want to do. i like these simple features because the functionality is there when i need it, it isn't thrown in my face when i dont, it has enough configurability to make it fit my workflow, and i dont need to install additional software to do what i want.