Reality is that Zoro is the only one who can kill Kaido and that Oda himself wants to make Zoro into the strongest character of all times. Reality is that Kaido must die because he will not abandon Wano and reality is that manga has been preparing us for Kaidos death for quite some time.
Reality is that ryo destruct inside living being CANT kill anyone. Reality is that Zoro is about to be proclaimed the new Sword God of Wano following into the footsteps of the old sword god ryuma.
The death of Kaido is inevitable and Zoro is the executioner, it is what Oda himself wants. Once it happens, you will look back and realize how pointless the struggle against it was but someone has to entertain us afterall so no biggie.
Chaves-chan reading Two Piece, nothing new.