Two hundred years ago, the horse was synonymous with powered transportation. Nobody imagined that a cart could move at all, let alone move faster, without the horse to pull it. Horses were fundamental to how the world worked — from how we tilled fields to how we communicated (the Pony Express). But within a few decades, horses were rapidly and all but completely replaced as a transportation technology. They were replaced not because they had an extremely destructive impact on the environment (they did), but because a new technology (automobiles) outperformed the horse in delivering value to consumers. The market quickly decided that cars and other forms of mechanized transportation provide better value than animal-powered transportation, and the rest is history.