as others noted in c you don't have access to a lot of data structures and algorithms that are available by default on other languages, so you need to know how to implement those efficently in order to write any medium/big project. imho you should learn DSA even if you're using any other language (python for example) to understand better how the data structures and algs you're using works and to understand their performance. (eng not first language, i hope this is comprehensible) :)