Lol. Even when that dialog worked as intended, it was total crap! It mostly worked for certain menu items only.

Fun game: try to remap Ctrl+a to select all, Ctrl+c to copy etc to mimic unix/windows. (or god forbid, to make your limited mobility device that cost thousands of dollars several years ago to work on your work provided macbook pro)

Every single app will behave differently and you will see how broken usability/accessibility is on OSX. Some examples for Ctrl+c:

on Firefox, Ctrl+c will move the cursor to the end of the text area while cmd+c will still work as copy, despite the menu hint showing Ctrl+c next to edit>copy.

On Notes.app it will work fine and cmd+c stops working (correctly).

On safari, calendar and most apple office stuff ctrl+c just do absolutely nothing. In some apps it shows ctrl+c next to edit>copy though, because why not