A ride hailing service needs to reach a critical density of available cars per km^2 to be useful. When you first install the app there needs to be someone nearby who will pick you up - if there's no car nearby most people will uninstall it. Additionally the more people use your app and the more drivers you have in an area the more effectively you can deal with idling (less variance in demand spikes - making planning easier for drivers). So on the contrary: I think this is a very difficult market to enter for new companies.