Earlier quoted context omitted.
An alternative possibility is that a rideshare company sees that Alice always takes the price that's offered so Alice receives the standard price, whereas Bob is price-sensitive so he receives personalized discounts on rides until the prices reach the amount that he's willing to pay.
This is what most airlines and hotels do, the best prices go on google flights and google hotels and the worst prices are in their own apps.
That's exactly right. This is a big market and this gives consumers another option to choose best priced rides. Think like you mentioned such as booking.com, sky scanner, Agoda, Expedia etc etc. Competition is good.