Humans have also created a lot. Domestic animal breeds for example. Nature left to it's own devices does not always do better than it does under the stewardship of humans. A garden is a simple example.
"Better" means nothing in this context anyway. Domestic breeds do not "do better" in some global sense either... often they do much worse on their own. You need to trim a horse or sheep's hooves. You need to check them for parasites. They need vaccines and antibiotics, and a tailored diet.
They're great for what we bred them for... live fat, die young... they're terrible in the wild. When you see pigs in the wild, they rapidly return to "boar" states, and lose those lovely "piggy" qualities you see on a small farm. Corn is great... for us. Without us, it all dies and can't reproduce alone.
A garden isn't our creation, it's our specific modification to suit our specific needs. It serves only us, and those forms of life which can adapt to us. It's also wildly artificial, requiring chemicals, or constant attention to achieve the "garden" state. A tulip is only "better" in a garden because it's one of the organisms we permit to live in the garden. Obviously the dandelions are much "better" overall though, because given a month alone it will be their garden, and not the tulips'.
