Today, assembly language would not be your first choice for building a data structure. But in the past, data structures were more easily built with assembly language than with the other programming languages of the time. In the first book written about data structures, The Art of Computer Programming by Donald Knuth (1968), the examples were done in assembly language.
Times have changed. Today most programming is done with languages like Java or C. Data structures are easily implemented in these languages. But of course, the programs are compiled, and ultimately they execute as machine code.
To understand what is really going on, it helps to look at data structures in assembly language.
(Review: ) What is a data structure?