I don't think we as a society or even humanity ever shared a vision. Though you may be right, I think it has more to do with our advancing knowledge which is relegating humans to just an animal ( a biological machine ). We used to think we were special. The center of the universe endowed with an eternal soul. Now we know that we aren't the center of solar system let alone the universe. Science has debunked all notions of the "soul" and it's presence in our bodies/organs/etc. And advances in AI is making a mockery of human intelligence in many specific fields ( though not on general level yet ). And recent studies of our brain and consciousness is starting to remove our last "mystery" of ourselves. And as neuroscience advances more, the "special" nature of our "unique" consciousness will probably melt away like our theories about the soul. There is even talk amongst neuroscientists/philosophers/academics/etc that the brain is just a "predictive machine" and that our sense of our "self" may be an illusion.
And of course add to that the growing economic and power disparity between people and the elite and a better understanding of history which is tearing down all the fake facade of american primacy or "western" civilization or even world civilization.
It also doesn't help that china has surpassed the US as the world #1 economy in PPP terms and will surpass the US in nominal terms in a few years.
In other words, our problem is that we are becoming more "aware/knowledgable". As they say, ignorance is bliss.