That’s a good point. Also in Laptops, you only have left Super due to short keyboard.

This avoids accidentally opening the menu in case you start to move or resize a window but decide to abort that action after already hitting the left Super key.

And the reason you shouldn’t use Alt (the default) for window manager actions with mouse is that many creative apps (e.g. Krita, Gimp, Blender) have actions that start with Alt+mouse click or drag.

Just try another theme. Note that whisker menu follows the theme of your panel (right click the panel at the edge of the screen and select panel properties). I’d recommend trying “Material Dark” for a pretty modern looking UI. (Some distros spell the theme as Materia.) Or if you have smallish display, try the compact variant.

The only problem I have with whiskers menu is that I cannot (easily?) switch the icon theme it uses for settings, logout etc within the pop-up menu. I would want to use KDE originated Breeze Dark for those icons.