People tend to think of this in black-and-white terms. The actual deal is that if Uber jacks up its prices significantly,
on the margin people will ride with Uber less.
Will their number of rides go to 0? No, of course not. But even if there is no other ride service available, there's still taking public transit, driving yourself, or, you know, not going out to whatever you're going to.
Remember also that even if Uber fully defeats Lyft and Lyft's service shuts down, there are plenty of companies out there better capitalized than Uber itself is. Those companies have so far decided to stay out of a "lose $2b per year" business, but if Uber can demonstrate that this is a "gain $2b per year" business, then Google, Amazon, one of the car companies, maaaaybe Apple, and probably a bunch of other companies can at that point launch their own service.
