Current absence of respectable and influential world leadership Revelation 6:2.
I do not suppose there is a verse anywhere in the bible that declares in the last days there will be no respectable and influential leadership in the world. But as often as the bible mentions kings, and rulers, governments and tyrants, etc. who have frequently attempted to rule the world (some with more success than others), it is quite apparent that in the last days there will be a vacuum of leadership. There are leaders, heads of governments, etc. however no one measures up to global leadership! With such apparent crisis looming over our head, that is the prospects of war, economic decline, the destruction of social order, deception and perversion, along with many other things, the world is starved for a respectable and influential leader.
One of the reasons we see weakness in world leaders at the end of the age is how easily they surrender to the Beast. With such a vacuum in leadership, the bible describes the turmoil of the nations as a sea in Revelation 13:1 (Daniel 7:2, 3). It is out of this turmoil and chaos created by the advent of these horsemen
(Revelation 6), and because there is an empty influence of leadership, that the Beast rises up. This great need invites this prophetical truth to be fulfilled.
I am also inclined to think that the first horseman in Revelation 6 is the Anti-Christ in an introductory role. After all, this is what the Beast does, he conquers and controls (Daniel 7:19). There is no reason why each of these horsemen could not exist together for while! The first horseman is described as conquering as he goes out, a continuous activity, so it could be that the other horsemen create great difficulty for him to conquer (overcome) which would in turn cause the entire world to admire him!