I have mixed feelings about discoverability. I'd usually rather functionality be available in a non-discoverable fashion than unavailable because designers couldn't figure out how to surface it in the UI. And, one of the things I like about vim and emacs is the interface can be extremely minimal with all the functionality I need behind key shortcuts and the like. (Although, emacs has a nice solution of `C-x C-b` list all the available shortcuts for the current window and `M-x` listing all the available commands.

The way I learned these shortcuts was reading macOS's help back in 2007, but the quality of documentation bundled with macOS has gone downhill quite a bit.