It's not even the underlying business model that's unsound. People will always need to get from point A to B, and the app based ride hailing model has completely revolutionized the fulfillment of this fundamental need. That's not going anywhere. Uber's problem is in their scale. You get essentially zero benefits and all of the drawbacks from massive scale in this industry, with the fact that your technology is trivially replicable by competitors, and brand loyalty is almost non existent. Uber is doomed in its' current incarnation. But my bet is that the future for ride hailing is one of hundreds of different competing local services around the world that focus on their locality, work directly with local officials and regulators, and provide good customer service while keeping overhead extremely low and operating profitably.