There is one more issue: Uber and Lyft massively increased supply. It is not clear, as you mention, whether this could have happened without investor aubsidy - but it is likely. Medallion allocation is a political subject which does not necessarily correlate with demand; and the established way medallion owners rent them out results in it being uneconomical for drivers to do more than a given amount of rides per shift - a result of which is that supply at peak demand (rainy days) is significantly lower than even what the medallion system allows for.