What is the meaning of the existence of this virtual world?

Buddhist practitioners can make use of this world to cultivate; sentient beings undergo retribution in this world, and apart from that there is nothing else of any significance.

What we face are clearly all just electrical signals—there is nothing there at all—yet we interpret them into a world of the six sense objects, resplendent and dazzlingly colorful. Those electrical signals are not real existents either; they are conjured forth from seeds that cannot be seen or touched. In truth, there is nothing at all in the world, and there is no world either. Sentient beings have an affliction of the eye like a cataract, and yet they insist on seeing the world and all the dharmas within it.

As for the world and all the dharmas within it, if you think they have meaning, then they have meaning; if you think they have no meaning, then they have no meaning. Dharmas have no mind, objects have no mind, scenes have no mind, the world has no mind—it is sentient beings who have a mind. Whatever meaning they assign to a scene, that is the meaning the scene has; whatever meaning they assign to the world, that is what the world means. If you have no mind, there is no world; if you have a mind, there are all dharmas.