Why Don't producers Prefer Latest Novels for Their Films?

During 1960s and 70s, thespian Akkineni Nageswara Rao would act as a hero in many movies based on the stories of successful novels written by then top writers. Writers like yaddhanapudi Sulochana Rani, Kommuri Sambasiva Rao were shot to fame with the...
Why Don't producers Prefer Latest Novels for Their Films? novels,films,akkineni nageswara rao,chiranjeevi,tollywood