Demand and supply meet at equilibrium when all players in the market are rational and have perfect information. In Uber's case, their poor UI meant that people

Demand and supply meet at equilibrium when all players in the market are rational and have perfect information. In Uber's case, their poor UI meant that people did not have perfect information and there was a market mismatch. What should have happened is that many people would have realized that paying $50 to drive a mile was absurd and walked, resulting in a more reasonable 2 - 3x surcharge rather than an insane 6x surcharge.