"Disenchanted" is the way that the wyrd often refer the modern world. At one time, magic was accepted as part of life. Mortals accepted that there were things beyond their ability to grasp. Things only glimpsed from the corner of the eye. Inexplicable things that could appear out of nowhere at any time and break the rules that they accepted as 'normal.'
This awareness existed in the mortal collective unconscious. But the proliferation of the modern scientific understanding of the world began to change this. Mortal imagination abandoned the idea that anything existed beyond comprehension. The belief in the ineffable was replaced by a belief in a quantifiable and understandable reality.
In mortal study, the concept of the indescribable gave way to the imagining that everything in existence must have a rational, if esoteric, explanation. This understanding of the world made access to magic and the supernatural increasingly inaccessible to mortal society. As mortal acceptance of the existence of magic waned, so did the effectiveness of its techniques.
Inversely, lines of scientific pursuit that had previously found to be unproductive began to produce results even as conventional magical practices became more difficult to tap into.
This change in how reality works was wrought by changes in the collective unconscious and changes in mortal understanding of their environment. Common understanding of how the world works, plays a significant role in how reality reacts to the will of living creatures. If a creature accepts the idea that magic works; then it does. If the belief is that magic is fake, then even phenomena produced by magic will have the appearance of a mundane and rationally explainable cause.
One sees what they expect to see in most cases. It takes a particularly remarkable magical occurrence to break through that confirmation bias in an individual. When someone who is not inclined to believe in magic encounters something magical, they don't perceive the fantastic nature of what they witness and their world view works to provide them with a rational or logical facsimile of the phenomenon.
Wyrd that rely on magic for their very existence suffered with this shift of the collective unconscious. The waning belief in mortal spheres reduced the overall flow of aether, functionally starving the wyrd creatures and leaving them vulnerable to the machinery of modernity.
While this state of disenchantment makes performing magical feats is more difficult than it once was, the aether produced by living creatures is abundant enough to support the creatures that remain. Mortals produce less aether than they did when the collective unconscious believed in magic, but there is still enough that those who possess belief and enough will can still shape the aether.
Magic is much easier to perform in remote locations where the weight of disbelieving mortal eyes are not around to cause friction. Central to the function of disenchantment is this: only as much magic can be manifested as those able to perceive it are willing to accept or ignore. Mortal society as a whole has trained its members to not accept a mystical explanation of events, and in doing so, have limited the viability of magic itself.
Only particularly willful individuals are capable of forcing magical phenomena into existence, countering the inertia of disenchantment.