Hiding the Last App
A long time ago — in the system 7 or 8 days, I’m sure — you could do this sequence in app…
Do some things in that app.
…and end up in the Finder, with all other apps hidden.
It hasn’t worked this way for ten years or so. But I still hit cmd-H many times a day expecting to end up in the Finder. Instead nothing happens. (The Hide command is disabled in this situation.)
It made sense to me because the Finder feels like it’s behind everything else. It feels like it’s the computer itself.
So now I get frustrated — many times a day — and option-click on the desktop. (I’m not a frequent cmd-tabber, though I realize that would get me out of using the mouse in this situation.)