It's always good to know about the basics. How memory work, memory allocators, cpu registers, compilers, &c.
You don't start racing cars by going to a F1 grand prix, you start with small slow karts and walk your way up. It's very visible when you work with people who started coding in C vs people who started with java/javascript.
I couldn't quantify what good it amounts to career progression
Because PL and compilers are interesting pieces of technology most use without understanding. Languages has become my favorite CS subject, my company is built around some ideas of transpilation.
Is it safe to assume we still have jobs for compiler concepts?
Yea, the nature of jobs is always changing, but I think the low level CS is safer than the webdev branch of the field.