John Gill Commentary Isaiah 40:23

"that bringeth princes to nothing; that maketh the judges of the earth as vanity." — Isaiah 40:23 (ASV)

That bringeth princes to nothing The great men of the earth, kings, rulers, and nobles, these he brings to the dust; and all their counsels, schemes, and purposes, come to nothing; and their monarchies and kingdoms too in time. Where are now the Babylonish, Persian, and Grecian monarchies, and those great princes that formerly reigned in them?

he maketh the judges of the earth as vanity their decrees and decisions to stand for nothing, as "tohu" and "bohu", the first of which words is used here; so that they are no more regarded and attended to.