That would be perfect if you left off here. I worked with C compilers and libraries without ever writing a line of C outside my code generator. A lot of companies and people do that. Those not needing to integrate with C code outside of API's just need a FFI with a number of systems languages available.

Truth told: system programmers either never need C or need it so few times it's almost totally unnecessary. Others don't need it at all. So, it's "not necessary for vast majority of things application or system developers work on." ;)