Why are data structures and algorithms so important in computer science?

In a word “VERY”.

I personally classify problems can be classified into 2 types:

  1. Logical
  2. Mathematical

To be good at the former one doesn’t require anything more than a high school certificate. These things are easy to program like printing multiplication tables of numbers etc. However, these problems though helpful in introducing students to programming, are of little significance when you encounter a real-world problem of industrial or academic interest.

To be good at later is where your knowledge in Data Structures and Algorithms come handy. Such problems require concepts of sometimes undergraduate level mathematics(necessary to write algorithms) and are of industrial and academic interest. Without knowledge of “DSA”, you may never even come close to solving such problems. Hence my short answer “VERY”.