Even if there WERE reliable autonomous cabs in the next 10 years (and I have serious doubts), switching to them would cause new problems for Uber: (1) Right now

Even if there WERE reliable autonomous cabs in the next 10 years (and I have serious doubts), switching to them would cause new problems for Uber: (1) Right now, Uber benefits from drivers underpricing the capital costs of their cars. Maintaining their own fleet would increase their costs. (2) Part of fleet maintenance is to replace vehicles every few years. This would flood the market with autonomous vehicles, each of which could potentially become part of a competitor's network (Think Lyft, but instead of driving your car, you'd have it drop you off at work in the morning, pick you up in the evening, and in between accept autonomous rides from the public).