Obviously, Anglo-American popular culture underwent a long-term seismic shift during the last century. A single article can’t begin to cover all its effects, from music to film and television to technology and its effects.
The materialist worldview had dominated the scientific-philosophical world for at least three decades by the time of the Depression, of course. Leading British philosopher Bertrand Russell had penned this classic defense of science-based atheism back in 1903. He was not the first to announce that ethically, we were essentially on our own with our “ideals.”
Philosophies such as French existentialism (major exemplars: Jean-Paul Sartre and Albert Camus) were responses in a broad sense to materialist atheism. They focused not on “ideals” so much as on the condition of the human person in a world rendered meaningless and absurd — where we have (as Johnny Rotten would “sing” years later) “no future” except the grave.