Wrong. None of the systems work. Because everyone gets exploited on its weak points and there simply isn't a perfect one. And just adding rules is making it worse and worse. Real capitalism could work if all costs would be fairly compensated. like the disposal of nuklear waste as an example. That's why nuclear energy is cheap, while it isn't counting in the disposal problem. That's why systems fail, because the true cost is not compensated. Bad employee treatment -> health cost. Bad infrastructure -> health cost and high maintenance cost. Etc. Under the same premises other systems might work as well but the natural an easiest one would be true capitalism. But since this is therapy and not the case none of the systems will work and from that perspective you are right no one has ever tried capitalism.