C is quite possibly the most successful programming language in the world. Originally replacing Assembly language in most applications, it also serves as the base for many language libraries and operating systems and is the base or inspiration for most of today’s modern programming languages.
Due to its widespread influence and longevity, it often serves as a gateway programming language for most learners. This is because being adept in C makes it easier to learn other programming languages.
This has made the language essential in all Computer classes. Its mastery allows programmers and developers to intuit the mechanism and logic of a code, even if they are not practiced in it. Also, due to its widespread popularity and embeddance, any expert in the field becomes essential for designing libraries, OSes, and similar tasks.
In a field where a lifespan of a decade is impressive, C has lasted for around half-a-century. It will continue to be relevant for the foreseeable future and any respectable CS course should offer it.