At least for surge pricing there is argument that you need to manage scarcity somehow. If everybody wants a ride because it’s raining, you can either rise prices or not, and make it a lottery. The latter is more fair, but the former has higher chance of bringing more drivers into circulation.
Could be, but that is a separate problem. For example places I've been in Europe have multiple competing services, even when Uber is present. But that's because the typical Uber business model where drivers are not professional drivers is banned most everywhere.
