I dunno. I am self teaching and I am finding things like compilers, os stuff, grammars, fsm, automata stuff, etc quite helpful. Like trying to write a parser helps understand the code I am writing a bit better, as well as understanding how abstractions like futures and promises could be working below the hood. While I understand that I may not be always right in the way I am understanding these stuff, I won't say they are completely useless.