It seems that between 1920 and 1970, there was much more progress in physics, computer science, biology, psychiatry, psychology, aerospace and space engineering, education than there was in the last fifty years. Something broke.
Except for the biologists, there was little disagreement? (Fwiw, AI may have had only 3 new ideas since 1970, but together with better hardware, they make a lot of difference, and may change science dramatically soon.)