It is due to the erratic swing of the pendulum of the universe that some ages of technology are able to advance farther than others and some ages of magic are able to discover more potent magic. The point at which magic and technology change, is not a clearly defined area. It is in fact an area of gray where both vie for dominance. Even now the pendulum continues on its endless path through time, heading toward the next age of magic.
The current reign of technology has provided for radical advances. As each new marvel is discovered, we become ever more dependent on the technology that created it. All too soon the pendulum will pass into the gray area that foretells the coming severance from technology. And foretell it does, as surely as the farmer's ax head whistling through the air foretells the severing of the chicken's head that lies on the chopping block.
Onward will swing the pendulum of the universe until all ties to technology are left far behind, and magic is the sole governing factor in nature. Surely this radical change will be the cause for mass hysteria and rioting. Civilization, as we understand it, will decay and turn to barbarism. That backward process will naturally continue until the leaders of the new age begin the process of re- civilizing the world. Of course it will be many years before civilization can spread beyond small isolated pockets. After all, the mantle of civilization is not one readily accepted by all.
The change of reign from technology to magic will cause untold hardships for those who survive. To say that the dead will be the only ones lucky enough to escape the hardships and suffering would not be entirely true. That's because sometimes even death is not an escape.
Trying to blame the change on any person or group of people is ridiculous. That kind of power is beyond the capabilities of mortal man. Blaming it on a god or gods is ludicrous for the gods have no power during the ages of technology. Suffice it to say that it is all a result of nature. No, it's not an act of vengeance or retribution for the manner in which technology has mistreated the environment. It's just the nature of the universe.