> C has immense cultural value. Lots and lots of extant source code, important source code
Yes, exactly! In my opinion, C for a programmer or computer scientist is like Latin for a medieval scholar. You don’t need to speak it fluently, but it’s good to know enough to read other people’s works and understand how concepts are expressed.
In practical terms, I think that almost any programmer can benefit from reading K&R and doing the exercises in it, even if they never go on to write “real” programs in C. The book is very short and readable, and finishing it is a much tinier task than learning the standard libraries and toolchain options and best practices and all the other stuff you need to be productive writing production-quality code.