Correct: Uber is not an established monopoly, but still contending every transaction. They are not competing just with Lyft, but the entire auto industry, transportation systems and shippers, and the convenience of delivery versus driving/riding across town.
All of this presupposes that Uber, though still growing fast, has reached a turning point. But what if nothing of the sort is going on? For a start, market positions in ride hailing look far from settled. Lyft’s rebound from also-ran is a sign that riders and drivers like choice. Barriers to entry may not be as high as often thought. In a city like San Francisco, many riders — and drivers — use both Uber and Lyft apps. And ride hailing is a decidedly local business, making it a constant city-by-city war of attrition.