IanHausen

Simple: because each fantasy race in Zelda was designed with their environment in mind, which is exactly how real world speciation occurs naturally over time. The Gorons of Death Mountain eat rocks. This is essentially an infinite resource, and they’re comfortable sleeping in caves, meaning they have no reason to work and toil. Thus, they are lazy as shit, allowing them to be goofy comedic relief who eventually face a serious threat - one that Darunia rises to fight for the first time since his ancestors conquered the mountain. The Zora of the rivers are carnivores who hunt fish. This lets them dominate the fresh-water bodies of Hyrule, but unlike the Gorons, they need to work to eat, so they’re all lean warriors. Thus, the Kingdom of Hyrule has allied with them rather than ruling then directly, giving them a free spirit compared to the other races (Ruto very much personifies of these traits). The Kokiri of the Lost Woods are perpetual children, physically and mentally. They are taken care of by a guardian deity, all their needs met by a father figure, who protects them inside a magical forest. They are therefore incapable of protecting themselves once the Great Deku Tree dies, leaving them cowering in their rooms until Link, an adult, comes to save them. The Gerudo live in a bone-dry, resource scarce desert. Their biology also dictates that they are incapable of producing children without finding men from other races. Both of these facts force them to go out into the rest of Hyrule and steal, be it food, horses, or boyfriends. All of these races have a distinct relationship with their environments. Their biology has been naturally selected over time to adapt to those environments. This leaves them feeling rich and fleshed out. If you want to craft interesting fantasy races, then you have to look at the factors which lead to speciation in the real world - people will resonate with it because they observe it every day.