Simplicity is all around us. Most things that we use and interact with; be it technology, infrastructure, and especially nature, are as simple as they can be. See, for something to really function well, it must be clear of any nonessentialness.
When a system is designed with more stuff that needed, it won't perform the best. Resources will have to be spent on maintaining and developing the added areas to the system, and overall there will be less focus.
Good systems, good creations, are focused. They do one thing well, and the rest will only make it worse overall. Of course, you can connect multiple systems together to create a network, an ecosystem, but before that happens, every system needs to it's own little thing well.
We, humans, like to overcomplicate stuff. We usually tend to think more is better. There is a deep-rooted belief in most of us, that to build something great, it needs to be multi-functional. Not necessarily versatile - that's a different concept. Yet we cannot see how the greatest creations, both human and by nature, are simple.
Notice the simplicity. You'll notice how to create better.