Why would there be any more or less supply than what's available via uber or lyft and why would the app be at fault when decisions are made by the driver? Now there are more choices you can be your own contractor or work for uber/lyft as an employee. People who have older cars and can charge less may drive down prices but I think there will always be a market for being driven in newer cars, suv's, luxury cars, etc. You can schedule rides ahead of time and set contract breakage penalties. All these can be suggested by the app but again it's up to the final decision made between the customer and driver.