Angels and demons have a relationship with the Material Plane. Even though both inhabit the fifth dimension, they can travel to the worlds that match closest to their vibration. Some think that the higher the dimension the higher the vibration. Each dimension has the same range of vibration. They all intertwine to make up Reality.
An angel travelling to a lower vibrational world will need to use much more energy than a demon travelling there and vice versa. As this world is kept on a low vibration, there is more demonic influence than angelic. It means that as the world lowers in vibration, there is less chance to raise it. Change comes in windows of opportunity.
As worlds go to Equilibrium, there is more love and less fear. There is independence rather than dependence. Knowledge is to bring abundance rather than mind control and deliberate poverty. People have property and responsibility for their lives; to live in relation to Natural Law and to bring a more positive future for every human being.
Those worlds above Equilibrium are called the Heavenly Worlds. As they go to the highest, there are less predators, parasites, and disease. Ecosystems become more symbiotic. An increasingly perfect system of reproduction and synchronized living. A lifeform living on these Worlds would find them increasingly peaceful and constant.
The more Hellish Worlds of the lower Material Plane are mainly city worlds. Nature is dead. All food is artificially made from compounds. People are subjected to a Master Race. They have been specifically altered to love their oppressors as their gods. A reality where most people exist to be used and eaten at will and to be thankful for it.
The lowest Hells are the worlds of predators. They are in a constant state of war. A constant cycle of chaos. There cannot be any peace in a hierarchy. Existence is to destroy others and become dominant. The only goal in life is to have the privilege of producing the next generation of chaos. There are few resources on these worlds.
It is believed that humans were created as slaves to serve an alien race called, the Anunnaki. What is more of a concern is that these aliens are evidenced to have returned and are manipulating this world back to one where they can rule supreme. There is lots of evidence online of eugenics, but also transhumanism. This would create the world mentioned in past manuscripts. The Age of the Nephilim. This would be like the hellish world described as second from worst to be born into.