>>52353685Natu is stylistically intended to be a simple design to fit the totem motiff. When you look at Natu and Xatu, that simplicity is conveyed to help you understand the design and what it's supposed to be. Compared to contemporary birds like Dodrio, Fearow, or Pidgeot, it stands out for this.
Fletchling in contrast is simple because it's your small first stage. It being simple is just a part of the art style and isn't intended to convey anything further than that. The trouble here comes from the fact that Fletchling and Natu coexist, with Natu's design untouched. Natu's simplicity isn't unique that much anymore, and due to outside influences, its design is hampered from accomplishing what it set out to do.
In short, due to Pokemon's decision to give every Pokemon a practically new art style and essentially turn away from a more cohesive unified art style for all Pokemon, Pokemon with designs that are supposed to stand out for one reason or another tend to fall to the wayside because it can just be interpreted as another Pokemon.
