I learned C in school. I’ve never written it on the job, but knowing it & the general Unix programming model does mean I can debug weird build errors and have and understand the source code and documentation of C libraries like sqlite. Actually come to think of it, I did write some C style C++ to make a setuid binary at Airbnb for binding & forwarding some ports on developer laptops.

I think C/C++ is very worth learning in general because the world’s most important and performant software is written in these languages. I wish I had a better command of C++; that language is the bar all others are measured against. “Is it faster than C? Is it more productive at maximum performance than C++? Is it safer than C++?” These are questions all other languages face.