This. I'm used to using extra keys (like the menu key or Capslock) for chording macros and personal shortcuts. In fact I get gaming keyboards with the customizeable keys (usually perma-bound — perma-binded? — to ctrl-, -2, -3, -4, -5 respectively) so they can be easily trapped and redirected to common macros.
I think the Super key was developed on the same principle.
People joke that the editor Emacs' name is an acronym for Edit Meta Alt Ctrl Super (all the modifiers but Shift on a very complex keyboard of the past) since it uses modified keystrokes for most of its functions, though really only Ctrl and Meta
Well, that is one advantage, that it's somewhat easier to remember Super+P than Ctrl+Alt+P.
But of course, it's also just a key which likely won't conflict with keyboard shortcuts used in applications. By convention, Super is only used for OS-level shortcuts.
If the Windows key didn't exist, Ctrl Alt would work just as well and wouldn't require anything else to remember because all OS level shortcuts would be Ctrl Alt shortcuts that wouldn't conflict with any applications.
Using Ctrl Alt would also be faster and more accessible because they are on the right and left instead of the current Super key (Windows) being only on the left.
I have been using key shortcut chaining in my WMs for freeing up more application hotkeys and also make them easier to remember. And it it still quite fast.
Starts them off by Ctrl+T, then for example:
A (Audio) - [P, Pause; N; Next; V, Volume]
R (Run) - [B, Browser; I, Inkscape; S, Spotify; Q, SQL editor]
And a lot more. The mnemonics helps me remember them, and Ctrl+T, R, B is quick enough to launch a browser.
It's somewhat useful for some keyboard shortcuts that literally could be replaced with a different key but yeah it's somewhat silly on its own. This will be downright stupid.