There should be a mode where you can choose to have the "activities" menu overlay the desktop, i.e. it shouldn't make the desktop wallpaper shrink, maybe make it a somewhat transparent overlay over the wallpaper. The reason I think something like this is really necessary is that too many things are moving, popping up, popping down when using gnome-shell. Too many things zoom, re-adjust, compare with the side-bar there as well. This is annoying for many users and can easily cause headaches when you are not used to it.

So I really think there should be a "fewer-movements-and-more-stable-windows-mode" for gnome-shell. That's why I would propose something like an activities menu that doesn't make the wallpaper shrink but is just an overlay, kind of like a dock that pops up and hides without changing geometry of the rest of the screen.