I fully agree that the processed food industry is a problem, but I find these superfoods to be a marketing hoax.
All fresh seeds, vegetables and fruit are healthy and deserve to be eaten. Local, seasonal products that are native to your climate are often better than exotic options.
So if you have the money, there is no reason not to buy superfoods, but if you are just a normal guy like me, just try to eat fresh and buy what you like.

On topic, my favorite superfood is kale. But I dont put it in a smoothie, I like to stew it with potatoes like my ancestors have done since many generations :)