If black gets all 4 corners, it’s because white (the stronger player) sealed them in to obtain a superior position on the outside
If white gets all 4 corners, it’s because black (the weaker player) failed to defend them properly
Either way, it essentially means if one player gets everything they ask for while meeting little resistance, resignation is usually a pretty reasonable option for the player being led around.
Of course like all proverbs they have some basis in truth but are also filled with exceptions
My mother had a large button collection and often used it to fix our old clothes. (My parents both grew up in the Great Depression. Nothing was thrown away.) I too have a small button collection and have used it a couple times to replace a button.