With your new hivemind spores in hand, it's all so simple. The problem at the center of capitalism is that, in the pursuit of selfishness, our ethical bonds to each other are sacrificed. The mushroom spores spread through the planet, and as they synchronize to our minds they change the 'me' to 'us' and unite us into a single self with a single set of goals. The market, instead of being the thing that sucks wealth out of the weak for the benefit of the strong, becomes a tool for efficient distribution in a way that benefits all. A subtle shift in identity is all it took to save us from ecological and economical collapse, and all it took was a single night's stumbling through a cave.