There used to be a time when critics who wanted to abolish the international system abounded. They wanted to replace the anarchic system of states with central direction, often a world government of some kind.
Such critics usually hailed from the Left, ranging from Communists to “world order” proponents, but also included Realists, who sometimes entertained the idea of world government as the only way to secure peace. In the 90s, the idea of a centralized “cosmopolitan democracy” was fashionable for a while.
But now, it seems, this sort of criticism appears to have subsided. The critics have made their peace with the states system.
The probable reason is that the system of states has proven to be a highly flexible and resilient institution. Probably most importantly, as international war has subsided, it has become clear that peace and the states system are entirely compatible.