People don’t really ‘turn’ to atheism. They become atheists for lack of a better way of looking at things.
Belief is not an easy thing to cultivate. If you set a young person into a strict routine, control what they can read, and do your best to teach them ‘right’ ways of doing things, common Victorian child-rearing practice, then what they’re going to remember once they’re grown is the oppression, not the subject matter you sought to teach them.
Christians, even the Victorians, understood this but did as much as they could anyway to grow the body of Christ. These measures kept the faith alive but what’s happening to Christianity is the same thing that happens to all ideas that are wildly successful, it became the victim of that success.
America grew and grew and grew until it reached it’s goal, Manifest Destiny, to settle the entire space of land from Maine to Florida, all the way west to the Pacific. Once it ran out of space to grow outward, it grew upward, and now appears to be at a peak. It may find the room and inclination to grow further, but eventually the idea of America will become not as new and shiny as other things we can achieve in that ‘space’.
The same is true of Christianity. Modern society has internalized Christian morality, and so sees no need anymore for Christian mythology. So new myth is invested into, that’s still fundamentally Christian, just isn’t thematically Christian, like Star Wars, Marvel, and Harry Potter.
Worse than the thematics, is the throwing away of Christian mysticism. People imagine Western philosophy and science as somehow apart from God, not able to see that it’s just modern theology of the same sort that has been conducted for thousands of years. There’s simply no daylight between Western ‘humanistic’ metaphysics and Christian metaphysics, the two shade smoothly into each other like yin and yang.