Except some of us understand these concepts, see how they can be used, but yet don&#x27;t understand why we would ever use them.<p>In all these sort of articles I&#x27;ve never seen something that can&#x27;t be done simpler with a bit of mutability sprinkled here and there. Sure having something 100% pure is great, but I don&#x27;t know if I want that if it requires a 10x increase in complexity.