I wrote introductory blog post answer that. https://tech.iheart.com/why-fp-its-the-composition-f585d17b01d3 https://tech.iheart.com/why-fp-its-the-composition-f

I wrote introductory blog post answer that. https://tech.iheart.com/why-fp-its-the-composition-f585d17b01d3 https://tech.iheart.com/why-fp-its-the-composition-f585d17b0... TLDR; It's about the ability to compose. Category theory enables more general and powerful composition of components. That is not to say that without CT you won't be able to compose, it's just more cumbersome and less flexible.