A virus is a toxic, venomous thing that exists only to cause detriment to whatever it infests.
Even in terms of computer science, a virus is malicious software that was created only to destroy and wreak havoc.
However, no matter how dangerous a virus is to the world it lives in―that is, the world within the computer―a virus that lives in the digital world cannot pass through from that world into reality.
It is not a question of the malware not working hard enough, or not trying.
Rather, it is simply not possible for something made up of ones and zeros to attain a physical form of its own will.
Likewise, the world-consuming virus of this universe and the End itself, the Nightmare King, cannot pass through from what we perceive as reality into the realm of the Highest Existence.
Is that what the World Tree is trying to say?