YMMV massively depending on what exactly you're working in. I've found when I'm writing libraries that will be leveraged by other programmers, especially in a

YMMV massively depending on what exactly you're working in. I've found when I'm writing libraries that will be leveraged by other programmers, especially in a modern/high level language, insights I've derived from my understanding of category theory have been incredibly valuable. If you're working very close to the metal (eg, embedded), very close to non-technical users (UI stuff, edge layer business logic), or in less featureful languages, then you'll get much less value.